Harper has been out since April 26 with a torn ulnar collateral ligament in his left thumb. He was originally supposed to be out six to eight weeks after surgery.
"He’s itching and pacing,” Nationals manager Matt Williams said, via the Washington Post. “It’s one of those things where he’s 21 years old and if it doesn’t heal right it can affect him long term."
Although the Nationals are barely above .500 at 29-28, they are only 1.5 games out of first place in the National League East. Harper only appeared in 22 games, hitting .289 with one home run and 9 RBI, before being injured.
"We want to make sure he’s good before he can get back out here. We don’t know yet. I’d like to see back by the first of July," Williams said. "That’s a good target but we just don’t know how everything else goes."CORCORAN: Top studs and duds: The best and worst No. 1 picks in MLB draft history