Kenley Jansen went to the hospital with an irregular heartbeat on Thursday and the Los Angeles Dodgers have sent him back to L.A. for more tests.
David Roberts said Jansen was at the team hotel and didn't feel right. Jansen called the trainer and was taken to the hospital.
The right-hander has dealt with the issue in the past. He will visit a cardiologist and had his medication with him on the trip to Colorado.
"We're holding out hope it's not too serious," Roberts said. "In talking to the trainer right now, his mood is fine."