Guerra was diagnosed with a Grade 1 UCL sprain Thursday and will be sidelined 2-to-4 weeks as a result, Kevin Acee of The San Diego Union-Tribune reports.
Guerra missed the end of the 2020 season for personal reasons, and he could be sidelined to begin the 2021 campaign due to his elbow injury. While the right-hander could begin throwing prior to Opening Day, he'll likely require time to build back up before he's cleared to return to game action. Guerra made 14 relief appearances for San Diego last year and posted a 10.13 ERA and 2.25 WHIP over 13.1 innings.