"When he was up here for TwinsFest, he was messing around with a couple guys and cracked a couple ribs, so he'll be out a month," Ryan said. "He was wrestling around. It was some horseplay. He was out with a couple friends and the team and cracked a couple ribs fooling around. It wasn't a fight or anything. It was just bad judgment wrestling around."
It's bad timing for Swarzak, as Twins pitchers and catchers are set to report to the club's Spring Training complex in Fort Myers, Fla., on Tuesday with the first workout set for the next morning.
Swarzak, who posted a 5.03 ERA in 96 2/3 innings last season, is expected to be in the running as the club's long reliever this season.
The 27-year-old fared better in a relief role last year, posting a 4.05 ERA in 73 1/3 innings in that role compared to an 8.10 ERA in 23 1/3 innings in five spot starts.
Ryan said the Twins are still hopeful that Swarzak will be ready in time for the season. The Twins open the regular season at Target Field against the Tigers on April 1.
"He's going to be close," Ryan said. "He'll be out a month and then he'll ramp it up. He'll still have an opportunity. I'm not sure if he'll be ready yet but it'll be close."
Rhett Bollinger is a reporter for MLB.com. Read his blog, Bollinger Beat, and follow him on Twitter @RhettBollinger. This story was not subject to the approval of Major League Baseball or its clubs.