During Wieck's physical exam ahead of spring training activities, an abnormal heartbeat was discovered on an EKG. Further evaluation by doctors revealed he had an intermittent atrial flutter, Cubs head team physician Dr. Stephen Adams said in a statement.
Wieck's surgery to prevent a recurrence of the atrial flutter was successful, the Cubs said. He has returned to Arizona to be with the team during spring training activities, but he'll rest and rehab for the next week. After that, the Cubs will further evaluate him and establish a timeline for his return to baseball activities.
Wieck, 28, had a 3.60 ERA in 14 appearances for the Cubs in 2019. He's expected to be one of their key members of the bullpen this upcoming season.