Will Middlebrooks understands the deal.

"I know it's a cat-and-mouse game, for sure," he said recently.

This is the life of a major league rookie -- make adjustments, make them again and keep repeating the process. For his first 41 games, Middlebrooks weathered this storm about as well a major league first-timer could hope for. In his initial 21 games, he hit .306 with an .894 OPS and five homers. The second 20? It was .356 with a 1.022 OPS and four home runs.

But then Kevin Youkilis was traded.

In the seven games since the Red Sox' lineup merry-go-round ended thanks to Youkilis being dealt to the White Sox, leaving Middlebrooks as an everyday big league third baseman, the rookie has hit .148 with seven strikeouts, one walk and one home run. (Of some consolation is the fact the player he replaced is hitting .231 in his seven games with Chicago.)

The timing could be totally coincidental, but it's noteworthy nonetheless.

Middlebrooks and the Red Sox knew such a downturn would be inevitable at some point. It's just arrived at a somewhat inopportune moment considering the need for some sense of validation regarding the midseason maneuver. Before the trade, the 23-year-old hadn't gone more than two straight games without notching at least one hit. But one day after the deal, along came a first for the rookie -- zero hits in 11 straight at-bats.

"He has to make sure he doesn't get himself out and swing at strikes," Red Sox hitting coach Dave Magadan said regarding what Middlebrooks has to do to avoid prolonged bumps in the road. "As he progresses he's going to walk more. It's only natural in the way it happens with power guys, as teams start to fear him a little bit they become careful. He's got to keep swinging at strikes."

So, has chasing been the problem? According to BaseballAnalytics.org, Middlebrooks' chase percentage the last seven games has been at 28 percent, a significant jump from the 21 percent he totaled the previous month. Of his seven strikeouts over the span, five have come on offspeed pitches at which he has swung and missed.

In total, during his seven-game downturn, Middlebrooks hasn't swung and missed at any of the 57 fastballs he has seen. But he also hasn't managed a hit on any of the 22 heaters he has offered at. Translation: The righty hitter isn't squaring up the pitch against which he hit .474 on over the previous 18 games.

The three hits Middlebrooks has managed during the seven games post-Youkilis (single, double, home run) all came on sliders right down the heart of the plate.

Then, to add insult to injury, he came down with a hamstring injury late in the Red Sox' 3-2 win over the Mariners Sunday, forcing the rookie from the game. 

But as difficult as it may be to understand now (with statistical comparisons to Youkilis taking place on a daily basis), this too shall pass. It usually does when you're talking about a talent like Middlebrooks.

"They basically try and mix it up on him," Magadan said. "He's shown he can hit the fastball on the inner-third of the plate. He's shown he can drive the slider or anything off-speed from a lefty the other way. He's a hard guy to pitch to because he has a decent enough idea of the strike zone and a good idea of what he's looking for and the discipline to take what he's not looking for and stay with his plan. He's got a really good idea of how he's being pitched. It's just a really good approach. The guys in the minor leagues did a great job with him because he's pretty polished."

To understand the kind of alterations opponents are making when facing Middlebrooks, all one has to do is look at Toronto's recent strategy against the third baseman. The Blue Jays were one of three teams (joining Miami and Baltimore) who had faced the rookie in more than one series, with Toronto advance scout (and former Red Sox catcher) Kevin Cash clearly taking note of what worked and what didn't the first time around against Middlebrooks.

"At their place they threw me cutters away, and [at Fenway Park] they tried coming in," he observed. "That was different than the last time."

Prior to the last week, Middlebrooks had clearly adjusted, with all 11 of his singles that reached the outfield in the previous 20 games going to either center or right field. It was a departure from his first 21 games, in which almost of his 26 hits were placed to left of center.

Now comes the second phase.

"With the technology now and the video stuff, it's easier than it used to be to make adjustment on [hitters]," Magadan said. "An advance scouting team can sit there and watch every one of his at-bats and see what he had trouble with. To me, that's a big advantage to the pitcher. You never know how a pitcher is going to pitch you and you can look at video for hours on end and a lot of times it doesn't translate to success against a pitcher. From a pitcher's end, you can see where to feed a guy into certain holes and if you can put it there you can get the guy out. But he's doing a good job."

Then there is the part of the game that has nothing to do with pitch selection.

"I feel like the biggest adjustment is getting used to the atmosphere," said Red Sox outfielder Ryan Kalish, who experienced the ups and downs of a rookie season in 2010. "The game never changes. Obviously the players are better and you have to make minor adjustments here and there, but it's about being able to handle the pressures of Boston. Obviously he's doing a really good job of slowing the game down, because that's something that can catch up to you."

Nobody -- including Middlebrooks -- said it was going to be easy.

"It's baseball," he said. "Every team has a different idea of how they're going to approach you. I just have to adjust."