Nationals outfielder Bryce Harper will seek a second opinion on his swollen left knee from Dr. James Andrews, manager Davey Johnson revealed on Thursday.

“The negative news is that Bryce did a little running in the water and his knee has been swelling up,” Johnson said. “He’s going to see Andrews on Monday. He’s probably not going to be available to come off when he’s supposed to come off.”

Harper was placed on the 15-day disabled list on June 1 (retroactive to May 27) with left knee bursitis. He was supposed to come off the DL on Tuesday.

"We haven’t been real successful with our treatment here," Johnson said. "He constantly gets treatment here, but we’ve got to get that inflammation out of there."

Harper hurt the knee originally in Atlanta on April 29 while crashing into the fence in right field. Matters then became much worse weeks later on May 13 at Dodger Stadium when Harper collided violently with the wall in right field. He then aggravated the injury several times while sliding and fouling off a pitch against the Phillies on May 26, the last game he appeared in.

Harper tried to play through the pain in nine games after the incident in L.A., eventually realizing it required a stint on the DL. Harper is now taking the long view with the injury, saying he intends to come back only when he is 100 percent.

“I’m not going to rush it. I’m going to take as much time as I can to get right. I want to get back in this lineup 100 percent. I don’t want back in it at 80 percent,” he said.

“I’m trying to get as much treatment as I can, try to stay off of it, not do anything, run or anything like that. Just try to stay off it as much as I can.”