Broxton will be shut down from all throwing for 2-3 weeks and is likely to be sidelined for more than a month, including rehab time.
Mattingly said he wants Padilla to be the primary ninth-inning replacement, although he conceded that pitching on consecutive days will be unchartered territory for Padilla, who is coming off February forearm surgery after a career primarily as a starter. Padilla has one save this year, his first in 11 years.
"It's Chief, pretty much," Mattingly said, referring to Padilla by his nickname. "Back-to-back, we've got to see the number of pitches and how it goes. We have to find out. If he gets too many pitches, we won't do it. If it's a typical inning, 12 to 15 pitches, we'll see how he comes back. He's willing to do it."When Padilla is not available, Mattingly can turn to Hong-Chih Kuo, who inherited the role when Broxton collapsed in the second half last year and saved 12 games. He also can turn to Kenley Jansen, who was called up after spending five days at Double-A Chattanooga. Jansen saved four games late last season when Kuo was unavailable. Broxton said he was told he would be shut down for 2-3 weeks to allow dissipation of fluid in the joint, then resume throwing. He said he also had a pre-existing bone spur in the back of the elbow that showed up in a 2010 MRI, but that wasn't the cause of his latest trouble.
Broxton revealed to the club on Wednesday that his elbow has been stiffening after he pitches, and he had an MRI on Thursday. He also said it doesn't hurt when he pitches, but his velocity Tuesday night was noticeably decreased when he walked two batters on eight consecutive balls in a ninth-inning loss to the Cubs.
He was examined by team physician Dr. Neal ElAttrache, who told him the injury was probably the result of his joint opening and closing at high velocity "and the bones slam against each other. It takes a while to get the fluid in there."
He said he was told he could take three or four days off and continue pitching, but the best course of action would be to shut down and let the bruise completely heal. Broxton said he didn't think this injury was related to his second-half collapse last year.
"It probably started in the spring and caught up to me now," he said. "The ligament is fine, there are no chips or anything. It's just bruised."
Broxton is 7-for-8 in save opportunities, but has a 5.68 ERA with nine walks, 15 hits allowed and nine strikeouts in 12 2/3 innings.
Jansen was sent down over the weekend to make room for Kuo, who was rushed back from the disabled list. Although his ERA was 7.43, nine of Jansen's 11 earned runs came in two awful outings. The rest of the time, he was overpowering, with a total of 22 strikeouts and eight walks in 13 1/3 innings.
Ken Gurnick is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.