Could Sergio Santos be a potential buy-low candidate for the Tigers' bullpen?

Remember Sergio Santos? While he was most recently employed by the Toronto Blue Jays, Santos made a name for himself as a flamethrowing reliever for the Chicago White Sox in 2010 and 2011. He racked up 30 saves as the team's closer in 2011, but Tigers fans may best remember him as the poor sap left standing on the mound when Ryan Raburn and Miguel Cabrera capped off a seven run comeback with two home runs in the bottom of the ninth inning of a wild, 9-8 September matchup.

Three injury-riddled seasons later, Santos is a free agent looking to reclaim past glory. Could the Tigers be interested in him as a possible buy-low candidate?

*2015 Steamer projection

Who is he?

Santos is a 31 year old right-hander who was selected by the Arizona Diamondbacks in the first round of the 2002 draft. A top 100 prospect in 2004 and 2005, Santos spent time in four organizations as a positional player. A .248/.305/.393 hitter in six seasons, Santos transitioned to pitching in 2009 and made his MLB debut with the White Sox in 2010. He pitched 51 2/3 innings that year, allowing a 2.96 ERA and 3.10 FIP. The next season, Santos took over the closer's job in late April. He racked up 30 saves in 36 chances, allowing a 3.55 ERA and 2.87 FIP. After that season, he was traded to the Blue Jays for Nestor Molina, a young pitcher who still has yet to reach the majors.

Shortly after being traded to the Jays, Santos' arm troubles started. He missed nearly all of the 2012 season after having surgery to repair his shoulder labrum, then most of 2013 with a triceps strain. In 2014, a forearm strain led to over a month on the disabled list. When he did pitch, he mixed flashes of brilliance with bouts of extreme volatility. The end result? A 5.23 ERA and 1.37 WHIP in 51 2/3 innings pitched across three seasons for the Blue Jays.

Why should we care?

When he is on, Santos has a lethal fastball-slider combo that racks up a ton of strikeouts. He has 209 strikeouts in just 166 2/3 innings, a rate of over 11 per nine innings. Even during his injury-filled seasons with the Blue Jays, Santos was still able to fan 61 batters in 51 2/3 innings. His slider induced a 30 percent whiff rate in 2014, and has been just shy of that level for his entire career. His fastball still reached the mid-90s with regularity, and he also features a changeup that has baffled many a left-handed hitter.

As good as the slider can be, Santos' changeup might be the pitch that sets him apart from other relievers. Because of that changeup, Santos has held left-handed batters to a paltry .619 OPS during his career. Meanwhile, right-handed batters are hitting .236/.332/.400, a .732 OPS. He walks right and left-handed batters at a nearly identical rate, and his strikeout-to-walk ratios are almost dead even.The 113 point difference in OPS is largely due to power. Right-handers have hit more doubles and home runs off Santos, while lefties have been stuck pounding the ball into the ground 53.6 percent of the time. When they aren't whiffing on the changeup at a 20 percent clip, that is.

Why should we stay away?

Unfortunately, it's tough to predict whether Santos will ever flip the "on" switch again in his career. He has dealt with a plethora of arm issues over the past three years, and at age 31, he's not getting any younger. Santos has not pitched 30 innings since 2011. When he does pitch, he is remarkably inconsistent. Last season, he could barely go two weeks without imploding in an outing. He gave up two runs or more in seven of his 26 MLB appearances last season. Hence, the ERA in the mid-eights.

Then there are the command issues, which predate the arm trouble. Santos walked 55 batters in 115 career innings with the White Sox, a rate of 4.3 per nine innings. His command problems didn't improve much with the Blue Jays, though the constant battle with arm injuries probably did not help. In 2014, Santos walked 18 batters in 21 innings. He has walked 11.3 percent of the batters he has faced in his career.

Will he end up in Detroit?

Santos passes the Tigers' offseason checklist with flying colors. Power arm that throws 95 miles per hour? Check. Cheap reliever that might not get more than a minor league deal? Check. We can also throw in jokes about command issues or arm trouble. Despite the seemingly perfect fit, the Tigers probably won't look Santos' way. There are lower risks elsewhere on the free agent market, though few of them have Santos' tantalizing upside. Given that he's three years removed from an injury-free season, a rebound year might be little more than a pipe dream at this point.