Washington Nationals outfielder Bryce Harper was not in Monday's lineup and will probably also be out Tuesday because of knee bursitis.
Manager Davey Johnson told reporters before Monday's game against the Baltimore Orioles that an MRI showed no structural damage.
Nationals medical director Wiemi Douoguih told USA Today that Harper has inflammation of the bursa sac in front of his knee, but should clear up in a couple of days.
Harper could return as the designated hitter for Wednesday's game against the Orioles.
The Nationals placed left-handed pitcher Ross Detwiler on the 15-day disabled list with a strained oblique muscle. The move was backdated to May 16, so he is eligible to return Friday.
To fill Detwiler's roster spot, the Nationals recalled lefty reliever Xavier Cedeno from Class AAA Syracuse.
Also, injured catcher Wilson Ramos, out since May 16 with a left hamstring injury, will be out for another month.