But given the volatile nature of the position, the question has been raised: Are relievers worth long-term high-dollar contracts?
"It's probably the riskiest of all the ventures if you're going to go long-term," said former Indians and Rangers general manager John Hart, a senior advisor for the Rangers and an MLB Network analyst. "There aren't that many Riveras floating around out there, where you can almost slam the door."
Front-office executives are aware of the risk. The three-year, $21.5 million deal Armando Benitez signed with the Giants before the 2005 season is one of many examples of long-term relief deals gone bad. But that hasn't stopped the spending.
Last year, there was a run on middle relievers and setup men. Joaquin Benoit signed with Detroit for three years and $16.5 million. That helped set the market for Jesse Crain, Scott Downs and Matt Guerrier to land three-year deals ranging from $12 million to $15 million. Rafael Soriano signed a three-year, $35 million deal to serve as a bridge to Rivera in New York.
While they didn't offer the long-term contracts that dominated last winter, the Giants invested early this offseason to keep proven left-handed relievers Javier Lopez and Jeremy Affeldt. The club re-signed Lopez, a 34-year-old lefty specialist, to his first multiyear contract (two years, $8.5 million) and picked up Affeldt's $5 million option in order to retain the key members of their excellent bullpen.
"One of our strengths was our bullpen," Giants vice president of baseball operations Bobby Evans said. "They kept us in a lot of games when our bats weren't getting runs across the board, and they gave us time to put some runs on the board late in games. They played such a big role not only in 2010, but also in 2011, and we wanted to secure them as best as possible. ... It wasn't a huge increase to the payroll, but we thought it was well worth the investment."
Closers have again taken center stage this offseason. Jonathan Papelbon inked a four-year, $50 million deal with the Phillies and the Rangers brought in Joe Nathan on a two-year, $14.5 million contract with a $9 million option for 2014. And that's hardly the end of the list of proven closers poised to cash in this winter. Ryan Madson, Francisco Rodriguez, Heath Bell, Francisco Cordero, Frank Francisco and several others stand to earn lucrative deals.
Red Sox general manager Ben Cherington, now in need of a closer to replace Papelbon, stated his preference for signing relievers, noting the volatility of the position when he said, "The shorter, the better." And Phils general manager Ruben Amaro Jr. noted the inherent risk involved in handing out long-term deals as he discussed the acquisition of Papelbon.
"Yeah, four years is a little uncomfortable, but on a player that's had this type of pedigree, this type of background and success, sometimes you kind of go the extra mile to do that," Amaro said. "We feel like with his history, with his health history, with the way he takes care of himself, we thought it was the right risk. Clearly, more risk when you add more years, but we felt he was the right guy to take a risk on."
That seems to be the general consensus: An elite, healthy, proven, talented reliever -- especially a closer -- is worth the gamble.
But as Hart said, it might be more difficult -- and certainly more expensive -- to find a pitcher with all those qualities than to simply take a flyer on a low-cost, high-upside player.
Benoit, for instance, was originally a starter, then moved to the bullpen, excelled in that role for a time, struggled, needed surgery and missed the entire 2009 season. The Rays gave him a Minor League deal in 2010, and he was dominant after being called up. Finding relievers along those lines is a challenge, but they can become the most efficient blocks in building a bullpen.
"You can go out and troll the waters and really gamble on good arms, trick pitches and sometimes you can hit it -- and you can do it for cheap," Hart said. "They kind of fall out. You shake the trees, and the best buys are when you get these guys and kind of do it yourself.
"Then they become not-so-good buys when they jump out on the free-agent market, and you're in competition, and some clubs look at it and say, 'Hey, this is our missing piece. We've got to close down the seventh and eighth, so let's go.'"
There have been some shorter, frugal contracts given to effective relief pitchers recently. Hart pointed to the D-backs acquiring J.J. Putz (two years, $10 million) and the Rays picking up Kyle Farnsworth (one year, $3.25 million) as examples.
"I think the better deal is in the shorter term. You might have to pay a little more money to get in the game," Hart said. "I think in the long-term, you start jumping out four years on some of these guys, and boy, it's a big gamble."
That risk likely won't stop the signings, though. Instead, they're probably just getting started.
"I don't think it's going to trend down," Hart said. "If anything, it's going to stabilize or trend up."
That won't be good news for some organizations' bottom lines, or for other clubs that don't have the payroll to pursue proven relievers. It might even hurt relievers trying to live up to the expectations associated with big contracts. But in the end, Hart said, it's still a good time to be a relief pitcher.
"If I were a reliever, I'd be saying, 'Hey, isn't this great?'"