It was one of the final days of April 2007, and Jonathan Papelbon had, as was written at the time, "dug himself in for the long haul."

Just a month before, Papelbon had officially put starting in the rear-view mirror -- along with the potential earning power that goes with it -- in favor of living the sometimes combustible life of a closer.

It would be five years before free agency would come calling, but that didn't faze Papelbon. He had all the confidence in the world that as good as it was for the then-26-year-old, diligence and determination were going to keep things status quo right up until the ultimate payday came calling.

"I'm here to get my fair share of money," he said during the first month of what would be the Red Sox' 2007 championship season. "My main priority is to stay healthy and be able to make money, not to go out and try and hurry up and win a championship this year (at the risk of injury). It's not like I'm hurrying up and going back to the closer's role because we have a good team this year and I'm going to blow (my arm) out and try and win as many games as we can (at any cost). No, it's not going to happen.

"I've got a lot of money to be made in this game, whether it's with Boston or not. My goal is to make sure I'm ready to play every day and to make money, and you can't make money if you're sitting on the bench. That's the way I look at it."

The plan has seemingly worked out.

As of 12:01 a.m. Thursday, Papelbon officially became a free agent, and he has entered these waters riding on more or less the same wave he was coasting on five years before. He is healthy, productive, and has even triumphed financially despite not signing a single multi-year deal. (Grady Sizemore, who has roughly the same service time as the closer, inked a six-year, $23.45 million prior to the 2006 season -- the largest deal ever signed at the time by a player with less than two years of big league service. During that same span Papelbon has made $29.135 million.)

But now what? Papelbon will get paid, but the questions are how much, and by whom?

This is what we know as free agency begins:

- The Red Sox are seemingly ready to see how the market develops for Papelbon before diving head-first into an effort to re-up their closer, having not gone full bore during their exclusive negotiating period with the reliever.

- Papelbon is at least in the conversation when identifying the most coveted reliever on the free agent market. Other contenders for the top spot -- weighing in age and performance -- are Ryan Madson, Francisco Rodriguez and Heath Bell.

- Teams that would appear to need closing help (depending on the loss of their free agents in some cases) include the Red Sox, Philadelphia, San Diego, the Mets, Toronto, Minnesota and Baltimore. Other possibilities include the Rangers, the Angels (Jordan Walden had 10 blown saves), Washington (if Drew Storen is traded), Dodgers, Reds and Marlins (if Leo Nunez' legal issues don't get ironed out).

- Papelbon will not be setting anybody up, which he reiterated when talking to WEEI.com in August. "Cinco don't set-up," the closer said.

- The Red Sox offered Mariano Rivera a deal last offseason that was worth $15 million per season, with separate sources offering conflicting information if it was for two or three years. The offer came about, according to a source, after Rivera's representatives initiated discussions without the Sox.

This is what it all means as free agency begins:

- As Red Sox GM Ben Cherington suggested once again Wednesday, any expectation that after making it this far Papelbon wasn't going to test free agency would be unrealistic. "I wouldn't expect any closure on any of those guys any time soon," said Cherington of Papelbon and the Red Sox' other big-name free agent, David Ortiz.

- While the numbers when comparing Papelbon's '11 season to Madson, Rodriguez and Bell are similar, the Sox closer can enter into free agency with some advantages. He has managed to put up his numbers over the past six seasons in the pressure-cooker that is Boston without a hint of changing roles. (No pitcher in Red Sox history has closed for longer than Papelbon.)

- The multiple landing spots are limited somewhat by market sizes and approach toward the closing role. The idea that a team can uncover an inexpensive option to close out games, as was the case with St. Louis' discovery of Jason Motte, might catch on. Yet, while the days of four- and five-year contracts for closers might be history, there still figure to be plenty of organizations that value end-of-game certainty.

- If Cinco don't set-up, that means Cinco probably won't have the Yankees as an option.

- The Red Sox didn't have any sort of illusions regarding Rivera turning his back on the Yankees' two-year, $30 million offer last offseason. But by offering the future Hall-of-Famer a deal, the Sox were also ready to commit to Rivera. It begs the question: If such an investment was potentially going to be made to the 41-year-old, then why not Papelbon?

Here are some interesting numbers when comparing the pair: 

From 1996-2001, Rivera's first six full seasons, he pitched in 384 games, totaled a 2.16 ERA, struck out 427, had a 3.39 strikeout-to-walk ratio, limited opposing batters to a .205 batting average, and claimed 215 saves in 248 opportunities.

Papelbon numbers in his first six seasons a closer: 379 games, 475 strikeouts, 4.85 K/BB, .199 batting average against, 219 saves in 247 opportunities.

In the last six seasons Rivera's numbers are also extremely similar to those of Papelbon: 385 games, 1.98 ERA, 383 strikeouts, 6.38 K/BB, .206 batting average against, 224 saves in 244 opportunities.

And the numbers in '11? Again, almost identical. They don't have nearly the same careers, and are 10 years apart in age. But, for the life of a closer's contract, Papelbon and Rivera, for all intent and purposes, are the same level of pitcher.

Cases to be made. Opportunities to be had.

Papelbon is a free agent, no surprise there. What happens now, however, is anybody's guess.