The Nationals activated outfielder Bryce Harper from the 15-day disabled list Monday, and he homered in the first inning of Washington's game against the Milwaukee Brewers at Nationals Park.
To make room for Harper, the club optioned right-handed reliever pitcher Erik Davis to Class AAA Syracuse. Davis had a 6.23 ERA in five appearances.
Harper missed 31 games with left knee bursitis.
He was injured May 13 after colliding with the outfield fence at Dodger Stadium and reinjured it several times before the diagnosis.
In a four-game rehab assignment with Class A Potomac and Double-A Harrisburg, Harper went 4 for 11 with a double, a triple and a home run.
Entering Monday, Harper was batting .287 with 12 home runs and 23 RBI.