AaronGleeman.com

After seven seasons in Minnesota apiece Matt Guerrier and Jesse Crain both officially left the Twins yesterday. Guerrier is heading to the National League on a three-year, $12 million deal with the Dodgers, while Crain will be remaining in the division and relieving for the enemy after agreeing to a three-year, $13 million contract with the White Sox. Neither departure comes as a surprise, although Crain going to Chicago adds a little extra sting to the bullpen losses.

Guerrier was remarkably reliable and generally very underrated throughout his seven seasons in Minnesota and ranks as one of the best waiver-wire pickups in team history. Claimed from Pittsburgh in November of 2003 after the Pirates acquired him from the White Sox in a March of 2002 trade for Damaso Marte, he went on to throw 472 innings with a 3.38 ERA and allowed opponents to hit just .247/.308/.387 while earning a grand total of just $6.6 million.

He twice led the league in appearances, worked 70-plus games in each of the past four years, is one of just three MLB relievers to log more than 450 innings since 2005, and had a sub-3.50 ERA in five of his six full seasons. Johan Santana, Al Worthington, and Rick Aguilera are the only pitchers in Twins history to throw more innings with a better adjusted ERA+ than Guerrier. And the Twins were right to let him go.

Guerrier has shown some signs of decline, as his strikeouts per nine innings dropped from 7.0 in 2007-2008 to 5.4 in 2009-2010 and he lost a full mile per hour off his peak fastball velocity. And simply by virtue of being a 33-year-old relief pitcher with less than overpowering raw stuff and secondary numbers that never quite matched the sparkling ERAs his performance is likely to crumble before the Dodgers are done paying him like a top-of-the-line setup man.

Similarly, it's difficult to fault the Twins for failing to top the White Sox's bid for Crain when they demoted him to Triple-A less than 18 months ago and never fully trusted him as their primary setup man prior to this year. To his credit Crain returned from Rochester pitching better than ever with a 3.00 ERA and 92 strikeouts in 102 innings following the month-long demotion and was nearly unhittable down the stretch this year by allowing four runs in a 42-inning span.

Crain's second-half dominance can be traced to an increased reliance on his slider, as he used it a career-high 46 percent of the time after previously never topping 26 percent. His mid-90s fastball didn't go anywhere, but by throwing it just 42 percent of the time after never before dipping under 60 percent Crain became a more dangerous, unpredictable pitcher. Whether he can thrive long term throwing nearly 50 percent sliders, however, remains to be seen.

His change in approach and being four years younger than Guerrier made Crain my preferred choice to retain, but committing to three years for either pitcher would have been a misstep by the Twins. Their departures leave a pair of big holes in a bullpen currently in flux, but rarely do three-year deals for setup men work out well for the teams handing them out and if the Twins stay patient there will be capable relievers available at a fraction of the cost soon enough.

Crain is a Type B free agent, so the Twins will receive a compensatory draft pick between the first and second rounds for losing him (Crain was a second rounder himself in 2002). Guerrier is a Type A free agent, but by not offering him arbitration the Twins forfeited his new team's first-round pick, plus the same sandwich pick Crain brings back. Letting both Crain and Guerrier walk was the right call, but the decision not to offer Guerrier arbitration was less clear cut.

Receiving a three-year deal from the Dodgers and reportedly drawing two-year proposals from several other teams makes it seem like offering Guerrier arbitration should have been an easy call, but the situation is much more complicated. Offering him arbitration would've dramatically altered Guerrier's market value, as few teams are willing to forfeit a high pick for a 33-year-old reliever and in the past some lesser Type A free agents have struggled to drum up interest.

If the Twins offered arbitration and Guerrier found the market lacking it's possible he may have re-signed for a much more reasonable price, but it's also possible his agent would've advised him to simply accept, forcing the Twins into a one-year commitment worth around $5 million. I tend to think it was worth that risk, because bringing Guerrier back on a one-year, $5 million deal would hardly be disastrous and two compensatory picks carry millions of dollars in value.

With that said, it's tough to predict whether Guerrier would've accepted arbitration and even tougher to determine how many teams, if any, would've been willing to lose a first rounder to sign him. Offering arbitration to Crain was a no-brainer, because Type B free agents don't cost their new teams a pick, but unfortunately Guerrier was tagged as Type A by a ratings system that drastically overrates relievers and it forced a risk-versus-reward choice upon the Twins.

Guerrier and Crain will be hard to replace, as they combined for an average of 135 innings with a 3.40 ERA in the past six seasons, but out-bidding 29 teams for the right to give three-year deals to middle relievers is the wrong way to build a bullpen. Right now the bullpen's outlook may be grim, but smart teams rely on the fungible nature of relievers and the Twins are better off trying to find the next Guerrier and Crain than paying a premium to retain the originals.