On Friday afternoon at Wrigley Field, with the Cardinals trailing the Cubs 3-2 heading to the seventh inning, Mike Matheny called on left-handed reliever Zach Duke to replace his starting pitcher Carlos Martinez. Duke turned around Ben Zobrist to bat right-handed, inducing a fly out to left field, before snaring a weak liner back toward the mound off the bat of Anthony Rizzo. With the right-handed hitting Willson Contreras due next, Duke was relieved by right-handed throwing Matt Bowman, who promptly recorded the third out. All told, Duke threw just six pitches, three for strikes.
On its own, Duke’s appearance doesn’t appear noteworthy. Nothing spectacular happened, and Duke has pitched in a lot of games. In fact, over the past three full major-league seasons, Duke was about as likely as anyone in the league to make an appearance on the mound in a game.
So what made Duke’s appearance special? To understand that, it’s necessary to begin with the fact that this was his first appearance in an MLB game in 2017. As the regular season ended last season in early October, the Cardinals reported that Duke had undergone Tommy John surgery while also having a flexor muscle repaired in this left arm.
Tommy John surgery has become something with which all baseball fans are familiar. At this point, it’s no longer shocking to hear that a pitcher has torn a UCL in his throwing elbow. By my calculations, over 26% of pitchers who appeared in an MLB game last season have had this type of procedure.