Left-hander Dontrelle Willis left after seven pitches in a relief appearance Wednesday with shoulder tightness in his comeback attempt with the Chicago Cubs.
Willis walked Nick Evans, the first Los Angeles Dodgers batter he faced to open the eighth inning in a spring-training game, and then came out after throwing one pitch to the next batter, Brian Barden.
The 2000 National League Rookie of the Year left the field with a trainer and was pointing to his left shoulder. The Cubs' medical staff will re-evaluate Willis.
"It's a mild setback, I guess," Willis said, according to USA Today. "Hopefully, it's nothing serious and I don't miss a lot of time. It's probably just fatigue. Hopefully just a couple of days and I'll get back on it.."
Willis, 31, had retired last July after going 0-3 with an 8.53 ERA in four games with triple-A Norfolk in the Baltimore' Orioles organization, but he signed a minor-league contract with the Cubs, his ninth team, in hopes of making a return to the major leagues.
Willis last pitched in the majors with the Cincinnati Reds in 2011. He has mostly struggled as a starter since the 2005 season with he posted a 22-10 record.