With Spring Training fast approaching, MLB.com will take a look at a different aspect of this year's Cardinals squad each day this week. Today's topic: Who might surprise?
ST. LOUIS -- Trevor Rosenthal will enter Spring Training in an unfamiliar spot, with a role undefined and a future uncertain. But the newfound flux doesn't signify a reduced impact. Rather, it could be quite the opposite for a former closer seeking to rediscover the command that too often abandoned him in 2016, all while boasting added versatility.
Rosenthal is coming off a year in which he lost his job as closer and missed time due to a rotator cuff injury. The adversity mitigated Rosenthal's impact in 2016, but not the Cardinals' belief that he can still be a key bullpen piece. In fact, Rosenthal may just emerge as spring's biggest surprise if he can find a way to turn back the clock.
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The Cardinals' decision to have Rosenthal stretch out during Spring Training gives the club great flexibility in how he can be used. As it stands now, they have another closer in Seunghwan Oh and plenty of starters to fill out a rotation. But Rosenthal can position himself to be in the conversation for either if an opening arises.
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The opportunity to pitch his way into a setup role or to serve as a middle-inning reliever who can bridge the game to the back end of the bullpen is most likely where Rosenthal will wind up.
Regardless where that fit may be, Rosenthal has the potential to once again make a great impact. Remember that it wasn't but two years ago that he was considered one of the game's most dominant relievers.
From 2013-15, Rosenthal ranked fourth among all relievers with 278 strikeouts. His 93 saves from 2014-15 were tops in the Majors, and he owns the lowest postseason ERA (0.69) among all active MLB pitchers with 20 or more appearances.

He's fighting recency bias for the time being, as it's Rosenthal's tumultuous 2016 season that remains fresh in everyone's mind. Over 45 appearances last year, he posted a 4.46 ERA and 1.909 WHIP. Rosenthal did see his strikeout rate rise (12.5 per nine innings), but his walk rate (6.5) did, too.
How much of the command issues were related to the arm injury is unquantifiable. However, Rosenthal looked refreshed after coming off the disabled list in September. Yes, the sample size was small, but over seven innings, Rosenthal issued two walks, struck out eight and allowed one run.
It was the sort of performance that allowed Rosenthal to end the season with some momentum, and it gave the Cardinals reason to believe he's worth prioritizing again. Rosenthal will earn $6.4 million as a second-time arbitration-eligible player. Now the Cardinals await to see the payoff.