Peterson was diagnosed with an oblique strain Saturday, Tim Britton of The Athletic reports.

EDGE Analysis

Peterson was placed on the 10-day injured list with what was initially described as right side soreness, but he's apparently dealing with an oblique issue. Manager Luis Rojas said that the severity is between Grade 1 and Grade 2, and the injury typically carries a recovery timetable of up to eight weeks. While the team's medical staff is optimistic that Peterson could return sooner than that, he'll likely miss extended time due to the injury.