The fifth starter in the rotation is rarely relied upon to be a difference maker. But if the Cardinals win their third straight division title, it could come down to their decision to place their trust in Carlos Martinez's golden right arm.
While plenty of attention has (rightfully) been placed on the Nationals' super-powered rotation and on the Dodgers plan to scoop up every high-risk, high-reward pitcher available, the Cardinals have assembled a solid staff of Adam Wainwright, Michael Wacha, John Lackey and Lance Lynn. Martinez, who is set to make his first start of the season Sunday vs. the Reds at 12:10 CT on MLB.TV, could be the best of the bunch.
Armed with an upper-90s fastball, a power sinker and a developing changeup that seemingly has its own center of gravity, he may have the best pure stuff on the roster. All from a pitcher younger than Gerrit Cole, Trevor Bauer, Yordano Ventura and Matt Harvey.
Used primarily out of the 'pen as a two-pitch hurler so far in his career, Martinez's brief stay in the rotation last year gives plenty of reason to be hopeful. Though he struggled in his seven starts, posting a 4.45 ERA in 32 1/3 innings, it's important to note that not only was he thrust into the role midseason, but Martinez kept his strikeout rate above a batter per inning.
Perhaps most importantly for a pitcher with a relatively slight build -- he's listed at 6-foot, 185 pounds -- he was able to keep his fastball velocity in the mid-to-upper 90s during the extended outings.
Though there is obviously concern about stretching young relievers into a starting role -- with Joba Chamberlain used as a cautionary tale -- Martinez's upside is undeniable. Among all pitchers with at least 80 innings last season, Martinez limited batters to the seventh-lowest contact percentage, just behind the not-from-this-universe Clayton Kershaw.
It could all depend on Martinez's changeup, the pitch he needs to neutralize left-handed hitters. Last season, lefties hit .297/.387/.462 against Martinez and walked more times than they struck out. Therefore the Cardinals must have been happy with his 9-1 strikeout-to-ratio against lefties in March, even if it was only Spring Training.
That work seemingly paid off in his (albeit infinitesimally small sample size) one inning tune-up appearance against the Cubs on Sunday, when Martinez's 3-2 offering struck out the left-handed-hitting Miguel Montero on the third consecutive changeup of the at-bat.
With the division race looking tight and the Cubs hoarding enough young talent that they could appear on TLC, the choice between a capable reliever and gambling on an ace seems like an easy one. Perhaps Martinez does lack the ability to hold up over a full season, and maybe he never will be able to get lefties out. But that's a question that can never be answered from the bullpen.
Michael Clair is a reporter for MLB.com. Follow @clairbearattack on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.