BALTIMORE -- Red Sox left-hander Eduardo Rodriguez has suffered a third right knee subluxation in the last 16 months, and he was placed on the 10-day disabled list prior to Friday's game against the Orioles.
Rodriguez slipped and fell to the ground during his warmups in the bullpen prior to Thursday's start at Camden Yards, but he felt fine to pitch, although he wound up giving up four home runs and seven earned runs over 5 2/3 innings in a 7-5 loss.
"We put him on the disabled list after some swelling emerged overnight," said Red Sox manager John Farrell. "Given that this is something that has reoccurred, I don't have a timeframe for when he's going to be able to get back on a mound right now. We're hopeful that this is on the short end."

Rodriguez will get a second opinion from Dr. James Andrews on Monday.
To replace Rodriguez on the roster, righty reliever Brandon Workman was recalled from Triple-A Pawtucket.
With a team off-day on Monday, the Red Sox don't need a fifth starter until next weekend against the Tigers. Left-hander Christopher Johnson, who has won both of his spot starts for the Red Sox this season and pitched a shutout at Fenway on Saturday, is likely to fill Rodriguez's rotation spot.

"It's the same injury he's had in the past, basically, with his knee and his kneecap moving," said Red Sox president of baseball operations Dave Dombrowski. "We decided it was the best thing to do. We think we have a feel for it and can hopefully work him through it at this particular time period. We think it's best to put him on the disabled list and not take the chance and make sure he's not only physically sound, but mentally sound. We're hopeful it will be a short-term diagnosis, but only time will tell."
When Rodriguez suffered his first right knee subluxation in February 2016, he struggled mightily upon his return to action in the regular season, going 0-3 with a 10.03 ERA before being optioned to Pawtucket.
The Red Sox will be careful this time to make sure he is ready both mentally and physically before he is re-inserted into the rotation.
"I think given the way Eddie's progressed through it previously, we feel like we're going to give this not only bullpen settings to test it, but also possibly a game situation somewhere just so when he does return, he feels mentally confident in his physical status, particularly after the way he woke up this morning," said Farrell.
The second subluxation Rodriguez had was last December while pitching in winter ball.
Rodriguez is confident this injury isn't as severe as the one that kept him out of action for the first two months of 2016.
"I'm thinking this is better, because last time this happened, I went a long time without throwing a ball and I was able to throw a ball last night," Rodriguez said. "Like I said, I woke up this morning and I felt that."
Even with the benefit of hindsight, Rodriguez and the Red Sox don't think it was a mistake for him to pitch on Thursday.

"We checked with him repeatedly, multiple times between innings," said Farrell. "It felt like he was good to go, and he was actually executing a high number of pitches last night, so it's unfortunate that we're in the position to put him on the disabled list right now."
The timing of the injury is frustrating for Rodriguez, who has pitched the most consistent baseball of his career this season, going 4-2 with a 3.54 ERA while striking out 65 batters in 61 innings and holding opponents to a .222 batting average.
Though Rodriguez was on a roll entering Thursday's start, he is adamant that the slip in the bullpen had nothing to do with the way he pitched against the Orioles.
"No, that wasn't bothering me last night, I just woke up this morning and felt that," Rodriguez said. "I wasn't thinking of that, I was just thinking of pitching my game. I wasn't thinking of that all night. No, like I said, I just missed my pitches and I was right in the middle of the plate, and that's what happened. That's what I think happened last night."
Rodriguez hopes his visit with Andrews will shed some light on why this continues to happen to his knee.
"I don't know the reason, I have to wait and see what the doctor thinks about it," Rodriguez said. "I've been training hard, working this offseason and Spring Training and all season to be sure things like that don't happen anymore, so it's a little bit frustrating. For me it's frustrating because I've been working a lot so that thing doesn't happen anymore and wouldn't happen again, so I have to wait and see what the plan is after I see the doctor."