In these parts, it will always be difficult to separate Jon Lester and Johan Santana. 

For most, the relationship will always be defined by the trade that never happened following the 2007 season. Santana's team, the Twins, were interested in striking a deal with the Red Sox, but only if both Jacoby Ellsbury and Lester were involved. That, however, wasn't going to happen.

Ellsbury and some players. Maybe. Lester and a group of prospects. Perhaps. But just like the Yankees weren't willing to package together young pitchers Phil Hughes and Ian Kennedy, the Sox weren't packaging up their future starting center fielder and top of the rotation lefty.

Now here comes Santana. Heading into his start against the Red Sox Friday night in the series opener against the team that did pull the trigger on trading for the former Twins ace, the Mets, it must be therapeutic for Sox fans to reflect on something other than a deal that never was when talking of the two lefties.

Thanks to the Red Sox' 5-1 win over Toronto Thursday night, it is once again easy to decipher why the Sox wouldn't give up on Lester.

"There were many of us who were big believers in Jon's ability as a person, as a worker, and his commitment to the big games, along with feeling that there was so much more there that we hadn't seen because of the illness and treatment that followed," said Red Sox pitching coach John Farrell. "We felt that after talking to others who had similar experiences about the full year after we might not want to let a pitcher go who might be undervalued at the time. 

"Anytime we're talking about a pitcher the caliber of Johan Santana, who is one of the premier pitchers in baseball, certainly he's going to garner a lot attention and get a lot in return. We just felt like we had a top end of the rotation type of guy who we felt like at his age and what potential he was showing routinely that he should remain here with us."

Heading into the Sox' first foray into inter-league play this season, this is how Lester and Santana have matched up since the beginning of the 2007 season:

Wins: Lester 19, Santana 21

Games Started: Lester 42, Santana 42

Innings: Lester 263 2/3, Santana 287 1/3

ERA: Lester 3.75, Santana 2.32

Strikeouts: Lester 210, Santana 273

For Santana, the numbers represents the reason why the Red Sox were bracing themselves to give up some of their most valuable commodities, while also having to commit to the kind of six-year contract the Mets settled on.

"He's as close as you're going to get to knowing that you're going to get your money's worth," explained Sox third baseman Mike Lowell.

But while Lester still has some ways to go before entering Santana's realm of certainty, the idea that the Sox' 25-year-old will be making $11.625 million in 2013, the final guaranteed year of his new deal, compared to Santana's $25.5 million in '13 (also his contract's last guaranteed season) makes the dynamic very palatable for the Red Sox.

Lester's record this season still stands at just 3-4 with a 5.91 ERA, having given up just four fewer home runs than he surrendered all of last year, but his latest outing  did enough to rekindle the optimism of a year ago.

Here is exactly how Lester started easing his way back into the class of Santana, along with four more things we learned in the final game of the Sox' sweep ...

KEEPING HIS COMPOSURE IS KEY FOR LESTER

Coming into his start against the Blue Jays, Lester was allowing opponents a .318 batting average and a .553 slugging percentage with runners on base. 

In short, sometimes baserunners were more of a distraction than Lester would have liked.

This time around there as a difference. He still allowed hitters to reach base -- giving up eight hits and two walks -- but just one scored, and that came after Lester was pulled from the game with one out in the seventh when reliever Ramon Ramirez failed to prevent an inherited runner to score for just the second time this season.

Somehow the fact that Lester allowed baserunners in every inning but one of the seven he pitched in didn't seem quite as important as the final result.

"I think the one thing he did much better tonight, even when there were borderline calls he did not get, he did not let that effect his thought process and execution from that point forward," Farrell said. "That's probably the biggest outward sign of confidence, saying, 'OK, I made that pitch one time and I can make it again.'"

Although the stuff wasn't Lester's best of the season (even if he did use his change-up with more effectiveness than most of his previous outings), the hurler persisted. A curveball that had little command early on the game wasn't abandoned and ultimately became a valued commodity in the later innings.

"You hit a little bit of a rough patch, you think you can't get anybody out, so you need to just get back to the basics of throwing strikes and throwing to halves of the plate instead of just trying to throw blacked out pitches every time," Lester said. "Like I said, we can take a lot from this start and build off of it and hopefully carry it over."

And the biggest win for Lester was the simple fact that potential big innings were squashed thanks to a few key pitches. As Alex Speier previously pointed out, it had been a problem:

Start 1: 4 runs - 5th inning

Start 2: 5 runs - 2nd inning

Start 4: 2 runs - 4th inning

Start 5: 2 runs - 1st inning

Start 5: 2 runs - 4th inning

Start 6: 3 runs - 5th inning

Start 7: 2 runs - 1st inning

Start 7: 6 runs - 5th inning

Start 8: 4 runs - 6th inning

This time around? One run in the seventh inning, which equaled a big step in the right direction.

"I thought as he got into the flow of the game, he got better," said Red Sox manager Terry Francona. "He used both sides of the plate, used his cutter, used his change-up. He got a big double play. He kept trying to execute a game-plan. If he made a pitch and it wasn't right or it wasn't effective, he came right back and made a better pitch. He had a couple border-line and came right back with a better pitch. That was good to see."

MAY IS FOR BAY

The two-run homer that was misplaced by Jays right fielder Alex Rios, who allowed the blast to clang off the top of the right-field wall and into the Red Sox' bullpen, was Bay's 13th of the season.

(By the way, does anybody remember Rios batting Alex Cora's lone Fenway Park home run in 400 at-bats into the right field stands back on Aug. 31, 2006?)

"I honestly thought he caught it," Bay said. "It was a little bright back there, and I heard the roar of the crowd and then I thought he didn't catch it. I really didn't see much else until I saw the replay. It was 50-50. It wasn't one when right when I hit it, I was like, 'Oh, that's gone.' Sometimes it's better to be lucky than good."

What is amazing is that it was the 11th straight time Bay has gone deep with runners on base, setting a club record, and closing within one of the big-league mark. The only time the left fielder has notched a solo shot this season came when he put the Red Sox' ahead with a ninth-inning homer against the Angels' Justin Speier back on April 11.

Last season 15 of Bay's 31 home runs were without anybody on base.

Yet another trend that may be just as remarkable is Bay's ability to hit in the month of May. Most might think that this time through the season's second month is tops for his career. For the month he has eight home runs (tops in the majors) and 25 RBI (2nd only to Cincinnati's Brandon Philiips' 26) while hitting .278 and slugging .681. 

Then you start looking at Bay's previous Mays. There was the .330 average with seven homers last season, the .336, four-home run run in '07, and then the standard-bearing '06 campaign, In May that year he hit .321 with 12 home runs, including a stretch of 10 home runs in as many days.

"I know for a fact it isn't," said Bay when asked if he believed this to be his best May. "It's usually because my Aprils are so bad. But my old man would always say, 'May is coming up!' Maybe it's because April is kind of like a pseudo spring training. I don't know."

As for his current stretch, which had Bay hitting .364 with two homers and four RBI in the series with the Blue Jays, the slugger doesn't believe it's because of different approaches, either from the pitchers or his side of things.

"It's not really something I really noticed. It's not like since I'm in Boston teams aren't targeting me as the guy, I haven't noticed that. For whatever reason ... I don't know what the difference is," he said. "I don't really want to think about it. I just want to keep going out there and hope the hot streak continues."

PAPELBON ISN'T ALL ABOUT FASTBALLS

Red Sox closer Jonathan Papelbon wasn't pitching for what would have been his 12th save in 12 chances, but that doesn't mean his scoreless ninth inning didn't present value.

Five of Papelbon's 13 pitches were sliders, a pitch that is clearly No. 3 on his depth chart, but certainly made its presence felt against the Blue Jays. Aaron HIll was badly fooled on one 84 mph offering, swinging and missing badly, while Rios was finished off with the aforementioned slider.

"It's been there for me," said Papelbon, who did allow one hit to make it just one flawless outing for the closer since April 22. "I threw all heaters the night before so I went with some sliders this time."

In fact, according to STATS Inc., Papelbon has used his slider a lot more against right-handers this season than last, tossing it 17 percent of the time against righties compared to six percent a year ago.

"When he comes in with a three-run lead or more he's usually going to use that a little more so he can work on it," Farrell said. "It was a good pitch for him."

GOOD NEWS THURSDAY

Jed Lowrie had a good day without coming close to playing in the Sox' win.

First, the shortstop got news that if the strength tests on his injured wrist go as planned Friday there is a good chance he can take some grounders. And then Lowrie saw his bat go to work.

You see, for more than a month Ellsbury has been using Lowrie's bats, a Rawlings model made of ash. It's worked out pretty well, with the Sox center fielder notching a first-inning double to extend his hit streak to 16 games. It has been a stretch that has seen the leadoff hitter total a .342 average with five doubles, a triple, 10 runs, four walks, and seven stolen bases.

It has been perhaps the most successful bat exchange since J.D. Drew hit a home run with one of Daisuke Matsuzaka's bats in Arizona back in '07, prompting some of the Japanese media to ask if the outfielder believed there was "magic" in the model.

(As a quick aside, Red Sox pitchers took batting practice prior to the game in preparation of inter-league play, with Josh Beckett using Mike Lowell's bat and Tim Wakefield swinging his own collection.)

The positive information in regards to the injured didn't stop with Lowrie's dual-pronged happiness. Rehabbing starting pitcher John Smoltz began his 21-game rehab stint by tossing three scoreless innings in which he allowed one hit while striking out two for Single A Greenville in Augusta. 

WOULD RED INSTEAD OF WHITE HAVE MATTERED?

San Diego starter Jake Peavy turned down the chance to be traded to the Chicago White Sox Thursday for four pitchers.

In these parts it recycled a question being tossed around throughout last offseason: Would Peavy accept a trade to the Red Sox if a deal had been worked out with the Padres?

While it was first reported that the Yankees and Angels were the lone American League teams on Peavy's list of clubs he would accept a trade to, the 28-year-old told WEEI.com during the World Baseball Classic that the Red Sox would have been an acceptable destination.

"Boston was a place that I told the Padres I would certainly be interested in playing," Peavy said. "I don't know if there were any talks. I gave the Padres a list and Boston was on that list. Boston was a place I told the Padres I would be interested in playing. Set that straight for sure."

While the Red Sox kicked the tires on Peavy, there were no substantial talks, with concern over how the starter's success would translate to life outside the pitcher-friendly PETCO Park in San Diego, and the National League.

And while the consensus was that the power pitcher would be solid no matter his home, whether or not the results would approach the value of his contract was another huge concern. If the Red Sox didn't have to give up talent and simply take on a contract that pays him $15 million next season, $16 million in '10, and $17 million in '12, along with a club option for $22 million in '13, it might be somewhat palatable. But that was a big 'if'.

That's why the price the White Sox were willing to pay seemed fairly extravagant in the eyes of many in the baseball world. In the end, however, none of it mattered and we're still left wondering where Peavy actually might want to play besides San Diego.