Knee swelling puts Rodriguez on DL

BALTIMORE — Red Sox lefthander Eduardo Rodriguez was placed on the 10-day disabled list Friday after re-injuring his knee on a fall from the bullpen mound.

Rodriguez slipped off the mound during the latter stage of his warmup for Thursday night’s start against the Orioles. He declared himself OK, but ended up allowing four home runs in a 7-5 loss.

Turns out, the tumble Rodriguez took before the game was not so harmless.

“We put him on the disabled list after some swelling emerged overnight,” manager John Farrell said Friday.

“He tweaked his knee once again,” said Dave Dombrowski, the team’s president of baseball operations. “It’s the same injury he’s had in the past, basically with his knee and his kneecap.”

Rodriguez missed the first 51 games last year while on the disabled list with a right patella (kneecap) subluxation.

Dombrowski said Rodriguez will visit orthopedic surgeon Dr. James Andrews on Monday for a second opinion.

“We think we have a feel of it and we hopefully can work him through it,” Dombrowski said. “But we think it’s best to put him on the disabled list and not take a chance. We’re hopeful it will be a short-term diagnosis, but only time will tell.”

The move came as a bit of a surprise, given that Rodriguez on Thursday insisted the fall in the bullpen had nothing to do with his performance.

“I just threw a pitch and my foot landed in a bad position. I went down. Nothing crazy,” he said.

Rodriguez had won four straight decisions before Thursday’s loss. He is 4-2 with a 3.54 ERA in 11 games, 10 of them starts.