Lovullo said Walker’s injury news “came as a surprise” to him. However, Walker will be going for a second opinion in hopes that he doesn’t have a UCL injury or possibly a tear in the ligament, which could result in him having Tommy John surgery and missing the rest of the season.
Walker’s injury happened last Saturday when the right-hander left his start against the Dodgers after pitching only two innings. At the time, he felt forearm tightness in his throwing arm.
If Walker is out for any significant amount of time, it will be a harsh blow to Arizona and its rotation.
The 25-year-old Walker was entering his second full season with the D-backs after he was acquired from the Mariners during the Jean Segura deal. Walker, who spent parts of four seasons in Seattle, managed to post a career-best 3.49 ERA and 8.4 strikeouts per nine innings while going 9-9 in 157 1⁄3 innings pitched across 28 starts with Arizona. This year, he has a 3.46 ERA in 13 innings across three starts.
The Diamondbacks are off to one of the better starts this season in baseball, going 11-4. They entered play on Tuesday with a 2 1⁄2 game lead in the NL West.
Without Walker, their rotation is going to hurt even more since they are already without Shelby Miller. Outside of ace Zach Greinke, they only have Robbie Ray, Patrick Corbin and Zack Godley. They will probably look to internal help for the time being, with Braden Shipley and Matt Koch probably tabbed as the most obvious candidates. If the injury is worse, they may try to explore the free agent market or possibly the trade market down the road.