Brian Matusz on lower-back injury (updated)

SARASOTA, Fla. - If the doctors are correct in their estimations, Orioles reliever Brian Matusz should be able to resume full activities within one to two weeks following an MRI on his lower back.

Matusz has been diagnosed with a strained serratus muscle, an area located on the lower right side of his back.

Full activity is defined as "being able to get back on the mound and pitch," Matusz said today. "Obviously, we're going to be cautions, and obviously the goal is to be ready for the start of the season, but also be careful and make sure that it's 100 percent healed. But the trainers have said it all depends on the symptoms and how I feel."

Matusz had an MRI on Thursday after allowing a double and home run the previous day in one inning against the Braves.

"Initially, the consensus was there was a bone bruise on three different ribs," he said. "Dr. (Derek) Papp took a look at the MRI and there's just some inflammation in there around the ribs. A strain of the serratus. So the doctor said I'm looking at about a week to two weeks before being back to full activity, but it's all depending on the symptoms and how I feel. We're just going to treat it accordingly and go day to day."

The discomfort started while Matusz was throwing his second bullpen session in camp.

"As spring starts, there's always something," Matusz said. "Getting back on the mound, there's always, 'I feel a little tight here, a little sore here.' I just feel a little sore on the right side."

Matusz underwent arthroscopic surgery on his right shoulder the day after the season to repair the AC joint and clean out about one centimeter of arthritic bone.

"I feel like I had the surgery this offseason on my right shoulder, and with that being 100 percent now, I feel like I'm getting through on my right side a lot better," Matusz said. "I don't know if there's any correlation with that or just getting through the ball better, but it was a little bit sore. But I was still able to pitch and kept going and it was one of those things that instead of getting better, it got worse and after the outing the other day, I think it was Wednesday, I was in some pain, so I approached the trainers and fortunately the trainers and Buck (Showalter) recommended getting an MRI.

"I'm glad that with their recommendation, we were able to get an MRI sooner rather than later."

The pain worsened when Matusz threw with maximum effort.

"That was the thing. Even when I was feeling a little bit sore over the last 10 days or so, I was able to squat and sprint and run and do everything normally," he said. "It was just getting on the mound and going max effort. That pull through on the right side. Once I realized it affected the way the ball was coming out, that's when I thought there was reason for concern."

Strained serratus muscles are common in rowers.

"I've heard either rowing or pull-ups or things of that nature," Matusz said. "Rowing and pull-ups, that's part of our training process, so that could be factored in to being a cause. Who knows what caused it or what the reason is? Good thing is we know what's wrong and how to treat it, so we can be proactive and get healthy.

"With this injury, it's nice that we caught it early and we're able to be proactive early and kind of get this thing taken care of and get 100 percent healthy. Ultimate goal is, as much fun as it is pitching here in the spring in Sarasota, the most important thing is being ready for the start of the season."

Meanwhile, the Orioles have committed four errors today in Fort Myers, three by third baseman Steve Tolleson, and trail the Twins 12-2 in the sixth inning.

Eduardo Rosario homered off Parker Bridwell in the fourth and Jason Garcia allowed an unearned run in the fifth. Chris Lee was charged with six runs, five earned, in 1/3 of an inning in the sixth, according to MLB.com's Gameday. Odrisamer Despaigne has allowed two runs and three hits.

Mike Wright starts for the Orioles on Sunday against the Red Sox in Fort Myers. Dylan Bundy and Brad Brach also will pitch. Ubaldo Jimenez starts Monday against the Twins in Sarasota. Hunter Harvey also will pitch.

Update: The Orioles committed five errors in Fort Myers and lost 13-2.