Harper is expected to play with Triple-A Lehigh Valley through Saturday while they host Gwinnett for a six-game series, Lehigh said in a statement.
Harper is expected to take Sunday off and could possibly return to the Philadelphia lineup on Monday when the Phillies begin a series at Arizona.
Last week, Harper completed a 60-swing BP session at Citizens Bank Park. It was the first time he had swung a bat since his thumb was fractured by a pitch June 25.
The seven-time All-Star and two-time MVP is batting .318 with 15 home runs and 48 RBIs this season.
The Associated Press contributed to this report.