Rea (lat) resumed throwing off flat ground Thursday, AJ Cassavell of MLB.com reports.

EDGE Analysis

After sitting out the entire 2017 season while recovering from Tommy John surgery, Rea received a clean bill of health heading into spring training, but the right-hander never ended up making a single appearance after experiencing shoulder issues in early March. The Padres later diagnosed Rea with a strained right lat, which had prevented him from throwing for nearly three weeks before his activity Thursday. It appears Rea will have to essentially go through an individual spring training all over again to build up to a starter's workload, which could take more than a month. San Diego may elect to move Rea to the 60-day disabled list in an attempt to gain some roster flexibility, as it's unlikely the 27-year-old would be called upon to join the big-league rotation anyway in the season's first two months.