The Pittsburgh Pirates sent outfielder Gregory Polanco to Triple-A Indianapolis on Monday.
Polanco, 22, is widely considered one of the top prospects in Major League Baseball.
Polanco, has a batting line of .241/.308/.349 with nine doubles, six home runs and 12 stolen bases in 64 games since being called up in June. He only has one hit in his last 30 at-bats.
Travis Snider recently received more playing time at the expense of the struggling Polanco.
Polanco had a batting line of .347/.405/.540 with 17 doubles, seven home runs and 15 stolen bases in 62 games with Indianapolis before his promotion. Before the season, he was ranked as the No. 10 overall prospect by Baseball America.
The Pirates (67-63) are five games back in the National League Central and just 1 1/2 games behind the league's second wild-card spot.
Polanco is expected to be brought back up when rosters expand Sept. 1.
The Pirates recalled outfielder Jose Tabata from Triple-A and activated shortstop Clint Barmes off the 15-day disabled list. The team also designated infielder Jayson Nix for assignment.