Tigers have shown interest in reliever Shawn Kelley

The Detroit Tigers have had an interesting offseason thus far, pulling off a couple of unexpected trades to make marginal improvements to their roster. With the outfield close to set -- I wouldn't say no to another signing, though -- the front office will turn its attention to the pitching staff. Both the starting rotation and bullpen need improvements, and it will be interesting to see how exactly the club allocates its limited resources (or if they blow the luxury tax out of the water).

One potential bullpen upgrade is Shawn Kelley, a right-handed reliever who pitched for the San Diego Padres in 2015. ESPN's Jerry Crasnick previously reported that the Tigers were interested in Kelley, along with Ryan Madson and Tommy Hunter. The 31-year-old Kelley has previous pitched for the Seattle Mariners and New York Yankees, and has put up solid peripherals along the way. FanGraphs' crowdsourcing project has him pegged for a two-year contract worth $8 million, a relative bargain given his stellar results in 2015.

Who is he?

A 13th round pick by the Mariners in the 2007 MLB draft, Kelley made a quick ascent through their minor league system. He pitched 46 innings at the major league level in 2009, allowing a 4.50 ERA despite a 4.56 strikeout-to-walk ratio. He improved his ERA (but not his lofty home run rate) in 2010 before undergoing "partial Tommy John surgery" on his right elbow. Kelley missed the rest of 2010 and nearly all of 2011, but returned to allow a 3.25 ERA in 2012.

Over the last three years, Kelley has been a different pitcher. He started throwing his slider more than ever, and a 20.4 percent whiff rate on that pitch has helped him strike out 201 hitters in 156 1/3 innings with the Yankees and Padres. His ERA hasn't been great -- he was at 4.39 in 2013 and 4.53 in 2014 -- but found a way to strand more baserunners last season, holding opponents to a 2.45 ERA in 51 1/3 frames.

Why should we care?

Slider-happy Shawn Kelley has been a strikeout monster, striking out over 30 percent of the batters he has faced over the past three seasons. That rate is nearly identical to what a lowly pitcher named Max Scherzer accomplished in 2015, but without the velocity. Kelley's fastball only averages about 93 miles per hour, but he pounded the strike zone in 2015, throwing first-pitch strikes 73 percent of the time.

Kelley's increased emphasis on throwing strikes paid off in a big way, resulting in a sharp drop in his walk rate. He walked just 7.3 percent of batters last year, his lowest rate since his rookie season in 2009. His strikeout-to-walk ratio was still solid even when the command wasn't, however, and sits at 3.33 for his career. The slider, in particular, has been a big reason for this; opponents are hitting .211 with a .336 slugging average off it over the past three years.

Why should we stay away?

Prior to 2015, Kelley was a pitcher whose excellent peripherals did not match his actual results. An extreme fly ball pitcher (he's at 48 percent for his career), Kelley has allowed 1.14 home runs per nine innings in 289 career appearances. Pitching in Yankee Stadium in 2013 didn't help, but he was a dinger monster when pitching for the Mariners at spacious Safeco Field too. The good news is that he has been trending in the right direction, allowing just nine home runs over his past 103 innings over the past two years.

Will he end up in Detroit?

Kelley is one name that many BYB readers have grown attached to, and for good reason. His excellent strikeout rate and improving walk and home run totals make for an enticing candidate to eat some important bullpen innings, and his overall profile -- the high fly ball rate, in particular -- matches the team's move to acquire Cameron Maybin, a rangy outfielder who will see time in left field. Kelley would come at a fraction of the cost of Joakim Soria and Darren O'Day, and may be able to match their production if 2015's improvements stick around.