MIAMI -- Cliff Lee has landed on the 15-day DL with a mild strain in his flexor tendon in his left elbow.
Ruben Amaro Jr. broke the news to reporters after Tuesday's 6-5 win in Miami.
Lee underwent an MRI on his elbow Tuesday in Philadelphia that revealed the strain. He experienced soreness in the elbow after his last start on Sunday against the Reds.
"We're going to be cautious with him, and there's no reason to try to push it," Amaro Jr. said. "Hopefully he's going to be ready by the time the DL's over."
On Wednesday, the Phillies recalled outfielder/first baseman Darin Ruf from Triple-A Lehigh Valley to take Lee's spot on the 25-man roster.
Lee said he initially experienced discomfort in his April 16 complete game against Atlanta. After undergoing treatment, it began to feel better, but the soreness returned in the later frames of his 6 2/3-innings outing on Sunday in an 8-3 win.
Lee tried playing catch on Monday, but he said he felt the pain on every throw, and trainers decided to conduct an MRI.
"I was hoping it would be really minor," Lee said in Miami after Tuesday night's win. "I don't know if this is minor. It's definitely not a ligament. A Tommy John thing is not what it is, so I think that was good, but we basically knew that from the tests they did before that."
The Phillies will be without Lee for a minimum of his next three starts.
"Cliff is a loss," manager Ryne Sandberg said. "Hopefully it was caught early enough with the mildness that it is. He's had some good outings up right to it. It just came on the day after [his Sunday start]."
Added Amaro: "It's not good news when you lose your No. 1 pitcher, but it's pretty mild."
The question now is if the 15 days Lee will be allotted to the DL is a realistic timeframe for his return.
"I hope so," Lee said. "I've never had anything like this. [Doctors and trainers] seem to think that without throwing for a week it should be quite a bit better. I don't know if it's going to be gone. We don't really know till you get there."
Lee will go the next seven days without throwing before testing it again.
"He's battled some elbow tenderness for about three weeks," said Amaro earlier Tuesday, before the results came back. "He's been able to pitch through it. He felt a little more uncomfortable in his last couple of innings Sunday. He saw Dr. [Michael] Ciccotti and Dr. Ciccotti felt it was alarming enough to do an MRI."
Lee's velocity on his fastball has dipped 1 mile per hour from last season, and it has consistently been 2 miles per hour slower than what it was in 2012, according to Fangraphs.com.
The 35-year-old left-hander is 4-4 with a 3.18 ERA in 10 starts this season.
Amaro was not ready to name candidates to replace Lee in the rotation, but the Phillies may go to Triple-A for Spring Training standout David Buchanan. Other Triple-A options include Greg Smith, Barry Enright and Sean O'Sullivan.
Ruf was batting .265 with three doubles, one home run and two RBIs in nine games for Lehigh Valley. He missed the first month of the season after sustaining a left oblique strain during Spring Training.
CEO Montgomery has surgery to remove cancer
MIAMI -- Phillies president and CEO David Montgomery underwent surgery on Monday to remove cancer from a portion of his right jaw bone at Thomas Jefferson University Hospital.
According to a statement released by the Phillies, the success rate in similar situations is very high and complications are not expected, although it is a significant surgery.
Manager Ryne Sandberg said the Phillies were playing with heavy hearts against the Marlins on Tuesday night.
"Our thoughts are with David, hoping for a quick recovery," Sandberg said. "I addressed the players about that. You could hear a pin drop in the room. Players came up to me afterwards with some questions about him."
Montgomery, along with co-owner Bill Giles, purchased the team in 1981 when he was also named executive vice president. Montgomery took over presidency in '97 when Giles stepped into his current chairman role.
"He's a guy that, in a lot of ways, is our biggest fan," Sandberg said. "In my experience with the Phillies, four years, he's a guy that sets the tone as far as being a family-oriented organization, first-class, doing things the right way and being the leader of the organization."
The Phillies' statement went on to say that Montgomery is expected to spend a week in the hospital and have some recuperation time at home before returning to work.
Revere feels healthy, but not in lineup to open series
MIAMI -- The Phillies were without Ben Revere in the starting lineup for the fourth consecutive game on Tuesday in Miami after he sat the entire weekend series against the Reds with a stomach virus. Revere, who led off and played center field in 30 of the Phillies' first 41 games, says he's feeling all better now.
Although manager Ryne Sandberg didn't start Revere on Tuesday, he agrees with the outfielder.
"He's fine," Sandberg said. "He came out and had extra hitting. He's going to be good."
Revere participated in some light batting practice and fielding before the game on Tuesday. He also hit on Sunday before Philadelphia's day off Monday.
"Getting a blow before I get out there, get going again," Revere said.
Revere, who is batting .268 with 17 runs and 12 stolen bases, thinks he'll probably get the nod to start on Wednesday, and he has been told he is likely to pinch-hit in a late-game situation Tuesday.
Revere says he picks the brain of Tony Gwynn Jr. due to how long he and his father have been around the game, and Gwynn Jr. will start in center field and hit eighth in the Phillies lineup on Tuesday. Both Gwynn Jr. and Revere serve well to cover a spacious Marlins Park outfield.
"It's beautiful scenery," Revere said. "Roof closed, ball's definitely not going to carry as far, so you get to go track down balls. It's a lot of field to play. This team hits very well. It's going to be times where you have to go after some stuff, get chances to make some great catches."
Sandberg has toyed with the idea of moving Marlon Byrd from right field back to center, where he played in his younger days, but the manager would prefer not to go that route.
"Maybe a game here or there," Sandberg said. "He's doing so well in right field. It's hard to move him out of right field because he's doing such a great job out there. That's a pretty hard position, especially at our place. That's one of the tougher right fields to play.
"He's shown it on the road too. It'd be messing with a good thing."
The Phillies have also gotten two starts in center from John Mayberry Jr., both over the weekend against Cincinnati.
"There's some good options there," Sandberg said. "It's also an opportunity to try some different things."
Sandberg, Phillies prepare for 20-game stretch
MIAMI -- Difficult as it may be to believe, the 20-game streak in consecutive days isn't even the longest the Phillies will see this season.
With a run that began Tuesday in Miami, Philadelphia can look to that and think it only gets tougher in June, when the team plays 21 games in 20 days. The stretch includes a doubleheader on June 28 against the Braves with a makeup of the postponed contest on April 15.
The good thing for the Phils is that after a three-game series at the Marlins, they travel home to face the Dodgers, Rockies and Mets, but they begin their series in Miami against a rookie making his second career start.
Right-hander Anthony DeSclafani earned a win in his Major League debut against the Dodgers, allowing two runs on seven hits with one walk and seven strikeouts.
"Another good arm from their system. Tall, lanky. Other than that, we're going to see him for the first time," manager Ryne Sandberg said.
Added Ryan Howard: "Looks like he's got some pretty good stuff; a good fastball."
Phillies hitters will probably take a number of pitches to get a feel for DeSclafani, but it also depends on his approach to the Philadelphia lineup.
"It probably just all depends on how he's pitching, if he's attacking or whatnot," Howard said.
When the Phillies hosted the Marlins in April, they swept the three-game set. The Marlins, however, lead all of baseball with a 17-5 record at home, so a carryover would be difficult to predict.
"Coming down here, it's going to be a real battle. We've got our work cut out for us, especially here in this ballpark," Howard said. "They're playing the way they're playing at home and nobody's really questioning it. I don't know if it's sleeping in your own bed -- whatever it is -- but something's working and they're just going with it."
Over the last 10 series against Miami, Philadelphia is 8-1-1 with a 22-9 record overall.
Like any long stretch of consecutive games without a day off, the Phillies will have to preserve their bullpen.
"When you're playing 20 in a row, starters are obviously going to try to pitch deep into games, give the bullpen as much rest as we can and keep our team in the game," said Kyle Kendrick, who starts Wednesday night.
David Furones is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.