CLEVELAND -- The Indians have known for several weeks that closer Joe Borowski was dealing with soreness in his right triceps, and they opted to let him pitch through it.

Borowski was sent out for four save opportunities in the season's first two weeks and blew two of them.

Now he's being sent to the disabled list.

The Tribe placed Borowski on the 15-day DL on Tuesday with a right triceps strain that is expected to keep him out of action for two to four weeks. Tom Mastny was called up from Triple-A Buffalo to fill out the bullpen, and right-hander Rafael Betancourt will take over the closing duties in Borowski's absence.

"Strength-wise, it was still very good," Borowski said of his arm. "That's why we thought we could push through it. We saw signs of making progress. But for every two steps forward, you take a step back. It felt like I was taking away from what these guys were accomplishing."

Borowski, who saved an American League-best 45 games last season, cost the Indians a pair of early victories in '08. On April 7 in Anaheim, he came into the ninth inning with a 4-2 lead and ended up serving up a walk-off grand slam to the Angels' Torii Hunter. And on Monday night, when entrusted with a 4-3 lead in the ninth, he gave up a sacrifice fly to Dustin Pedroia and a two-run blast to Manny Ramirez.

It wasn't difficult to discern why Borowski was having so much trouble. His velocity is significantly down from last season. Whereas Borowski used to routinely hit 88 mph, he maxed out at 83 on Monday night and was more often hitting 81.

So why did the Indians keep running Borowski out to the mound?

"You've got to give him a chance to see it through," manager Eric Wedge said. "He saved the first couple of games and one got away from him. So he was 2-of-3 in save opportunities coming into [Monday] night."

But after Monday, the Indians had seen enough.

"Even if he would have saved that game, seeing what I saw, I would have had a discussion with him," Wedge said.

In a discussion after the game, Borowski, Wedge, pitching coach Carl Willis and the team's athletic training staff all decided it was best to give the closer a rest.

"I'm kind of stubborn, and you hate to do it," Borowski said, "but I can't keep doing it to the rest of the team."

The 36-year-old Borowski said after warming up on Monday night that he felt like he was going into the game with an "unloaded gun."

It was mentioned to him that the Red Sox were not a team to get engaged in a scrimmage with, to which Borowski responded, "I could have been going up against my son's Little League team, and it would have been just as bad."

Wedge said Borowski first felt the triceps problem during Spring Training. When Borowski didn't show up in any Grapefruit League games for a significant stretch, Wedge downplayed the situation to reporters, saying the Indians were merely having him do his work on the side and in Minor League action.

And when questions about Borowski's velocity came up the past week, he and the Indians denied that he was injured.

Now that the cat's out of the bag, Borowski, who had an 18.00 ERA in five appearances this season, will be shut down from doing any throwing for several days. The Indians are encouraged that he came into spring camp throwing hard, and they hope rest will do the trick.

Borowski is no stranger to arm issues. A right shoulder strain held him out of action for most of the 2005 season. He insists that this injury is nowhere near as serious.

"It wasn't a red flag where I couldn't move my arm or anything," he said. "If I was to go out and test my strength, it would be pretty normal. It was one of those nagging things where, unless you give it total rest, it's going to nag you on and on."