Pierce had left shoulder surgery and is likely done for the season, Ian Cundall of Baseball America reports.
Pierce was a league average hitter (100 wRC+) in 34 games for Single-A Charleston prior to the serious shoulder injury. He slashed .252/.336/.390 with four home runs, six steals and a 28.6 percent strikeout rate in 34 games and is expected to have a normal offseason.