GLENDALE, Ariz. -- Kenley Jansen, whom the Los Angeles Dodgers will count heavily on this season as their eighth-inning set-up reliever, was cleared to resume workouts Friday after experiencing shortness of breath and difficulty sleeping Thursday night.
Jansen, 24, spent a month on the disabled list last season because of cardiac arrhythmia, which he experienced immediately after a game.
He spent a night in the hospital, during which his heart was shocked into normal rhythm. Because of that medical history, the decision was made quickly for him to see a doctor when he experienced these latest symptoms.
"(Dodgers trainer) Sue (Falsone) said it could be nothing and he could be back working out in 30 minutes," Dodgers manager Don Mattingly said. "They always monitor him pretty closely ... and this was something Sue didn't want to play around with. You always have to pay attention to stuff like that."
Jansen, who returned to the team's spring training complex and was seen headed to the practice fields in uniform at about 11 a.m., wasn't expected to do much more than play catch for the rest of the day. He was cleared by Dr. John Monroe to participate.
Mattingly said that ever since Jansen's issues last year, the team's medical staff has checked his blood pressure twice a day. Jansen is on medication and is supposed to avoid caffeine.
He has made one Cactus League appearance this spring, pitching a perfect inning with one strikeout Wednesday against the Oakland Athletics.
Jansen -- who only within the past couple of years converted from a catcher who wasn't really considered a prospect to one of the most promising pitchers in the organization -- set a major league record last season by averaging 16.1 strikeouts per nine innings. He posted a 2.85 ERA in 51 appearances, finished seventh in National League rookie of the year balloting and is widely viewed as a potential closer at some point, possibly later this year.