The bullpen has been a strength all throughout the Joe Girardi era, but injuries have wreaked havoc on the relief corps in 2012. Mariano Rivera made just nine appearances before suffering a season-ending ACL injury, and then a few days later David Robertson suffered an oblique strain that cost him a month on the DL. With their two best late-game arms out with injury, the Yankees relied heavily on Boone Logan and Cory Wade ahead of backup backup closer Rafael Soriano.

All of that work has thinned out the relief unit even though Robertson has returned. Wade is in Triple-A after allowing 16 runs in his last six innings and Logan leads the league with 43 appearances. He’s allowed a run in each of his last four appearances. The Yankees picked up Chad Qualls to add some depth and until we see Joba Chamberlain and/or David Aardsma on a big league mound, they shouldn’t count on them for anything. New York needs to add a quality reliever to their bullpen, someone to help take the load off Robertson and Soriano. The pace these guys are going at right now puts them at risk for burning out late in the season, something Girardi has done a masterful job of avoiding in recent years.

Trading for relievers is risky business, which is why the Yankees haven’t done much of it in recent years. Kerry Wood worked out well in 2010 and Damaso Marte has his moments in 2008, but otherwise they’ve built their bullpens via internal options and the scrap heap in recent years. Digging up another Wade — last year’s version, not this year’s — is probably not something they count on, so the trade market becomes an undesirable but necessary avenue to add relief depth. Let’s take a look at a personal fave and someone who should be very available since his team is not contending: Matt Belisle of the Rockies.

The Pros

• A failed starter with the Reds back in the day, the 32-year-old Belisle has quietly become one of the game’s most effective relievers. He’s pitched to a 2.82 ERA and 2.72 FIP since the start of 2010 (1.93 ERA and 2.27 FIP this year) with stellar strikeout (8.07 K/9 and 21.9 K%), walk (1.62 BB/9 and 4.4 BB%), and ground ball (51.7%) rates. Take out the eleven (!) intentional walks and it’s a 3.2% walk rate. That is getting it done.
• Belisle is a true three-pitch reliever, using a low-90s fastball to setup his mid-80s slider and low-80s curve. The slider is for righties, the curve for both righties and lefties. He’ll also throw a low-90s two-seamer and an upper-80s changeup, but very rarely.
• Thanks to those two breaking balls, he doesn’t have much of a platoon split. Belisle has held lefties to a .275 wOBA (22.7 K% and 6.9 BB%) and righties to a .294 wOBA (21.4 K% and 2.9 BB%) over the last three years.
• Belisle is a true workhorse out of the bullpen, throwing 92 innings across 76 appearances in 2010. The Rockies scaled it back to 72 innings across 74 appearances last season, but this year he’s up to 46.2 innings in 43 appearances. He’s tied with Logan (and a few others) for the most appearances in baseball and is third in reliever innings.

The Cons

• All of those appearances and innings may be catching to Belisle, as his fastball velocity continued to trend downward this season after a slight drop a year ago. He’s also throwing the fastball less frequently than ever before (just 46.9%), perhaps an indication that he’s having trouble getting outs with it.
• Belisle has a history of knee problems, including a torn ACL back in 2008 and offseason surgery to repair a torn meniscus after pitching though it all last season. He’s obviously been healthy enough to rack up all those innings, however.
• He’s not cheap. Belisle is making $3.775M this year — approximately $1.8M from here on out — and is under contract for $4.1M next season. His contract includes a $4.25M mutual option for 2014 with a $250k buyout. That’s not a ton of money, but he would be the third highest paid reliever on the club behind Rivera and Soriano.

Belisle has a whole lot to offer as a workhorse reliever capable of getting both lefties and righties out. That’s one of the biggest problems with the Yankees bullpen right now, there are so many specialists — Clay Rapada, Cody Eppley, Logan, Qualls — that Girardi has to use two or three of these guys just to get a handful of outs. Belisle’s a guy who has experience pitching in big-time offensive park and won’t require any sort of special treatment as far as matchups go. They could just stick him out there for an inning or two and let him go.

Reports indicate that the Rockies would have to be overwhelmed to trade Belisle, which is unfortunate. Relievers like Matt Capps and Mike Adams were traded at midseason with a year and a half of team control remaining at recent trade deadlines, giving us a pair of decent comparables. Capps fetched Wilson Ramos — an excellent catching prospect at the time — while Adams netted Joe Wieland and Robbie Erlin, a pair of Grade-B pitching prospects at Double-A. Rockies GM Dan O’Dowd is probably looking to hit a homerun like the Athletics did when they traded Andrew Bailey for Josh Reddick and others.

The Yankees have the pieces to swing a deal and Belisle appears to be a damn good fit, but again, trading for relievers is always risky because they have a tendency to suck for no apparent reason and without warning. If Belisle comes in and pulls a 2007 Eric Gagne, whoever trades for him will be stuck with him at a team unfriendly salary in 2013. The upside is that he comes in an dominates and is around next year, providing some protection should Soriano opt-out of his deal after the season. There’s an obvious need for another quality reliever in the bullpen, it’s just a question of whether the Yankees want to shore it up via trade or continue to do what they’ve been doing for the last few years and finding answers on the cheap.