Cardinals left-hander Marco Gonzales will undergo Tommy John surgery to repair the ulnar collateral ligament in his left elbow, Cardinals general manager John Mozeliak confirmed to reporters, including Derrick Goold of the St. Louis Post-Dispatch (Twitter link). Gonzales has reportedly been weighing surgery to repair an elbow problem, though the specific nature of the surgery, to this point, had not been definitively reported.

The 24-year-old Gonzales was St. Louis’ top pick in the 2013 draft (19th overall) and made his Major League debut with the Cardinals the next season, appearing in 10 games (five starts) and recording a 4.15 ERA with 8.0 K/9, 5.5 BB/9 and a 36.3 percent ground-ball rate in 34 2/3 innings. Gonzales, who rates as the Cardinals’ No. 7 prospect at MLB.com and No. 5 according to Baseball America, missed a significant portion of the 2015 season due to shoulder troubles. He pitched at Class-A Advanced, Double-A and Triple-A, compiling a 4.69 ERA in the minors. Gonzales also tossed 2 2/3 innings in the Majors last year.

The Cardinals’ pitching ranks have been thinned out substantially in the past nine months, with Gonzales and right-hander Lance Lynn each falling to Tommy John procedures. Beyond that, No. 1 prospect Alex Reyes, a right-hander, received a 50-game suspension back in November. The Cards added right-hander Mike Leake on a five-year deal in the offseason to replenish some of the depth in their rotation, which presently features Leake, Adam Wainwright, Michael Wacha, Carlos Martinez and Jaime Garcia. Left-hander Tim Cooney, who made six starts for St. Louis last season, is the likeliest candidate to be recalled and step into the rotation should a need arise.