Jansen experienced discomfort while running last week and had surgery to remove the growth Tuesday morning in Los Angeles. He will be on crutches for ten days and then wear a walking boot for three or four weeks.
Jansen, a hard-throwing, 27-year-old righthander, had 44 saves for the Dodgers last season. He had a 2.76 ERA and 1.133 WHIP in 65 1/3 innings.
Opening day is seven weeks away. A 12-month recovery time would put Jansen's return in the second week of May.
Only three other pitchers recorded saves for the Dodgers last season and none is on the team this year. Lefthanded reliever J.P. Howell finished the second-most games of any Dodgers pitcher still on the roster.
The bullpen was a weakness for the Dodgers in 2014, as relief pitchers lost a total of 17 games. Los Angeles was reportedly quite interested in signing free-agent reliever Andrew Miller this winter but he signed with the Yankees.
- Dan Gartland