Pedro Feliciano has been shut down because of an irregular heartbeat discovered during his initial team physical. After being sent to New York for a follow-up MRI, the left-handed reliever was back in camp Saturday, but will undergo more testing and will wear a heart monitor for several days.

“He has a heart condition that could possibly be very serious,” Terry Collins said. “That’s why while we are waiting for further results. He is not to be on the field.”

Feliciano, 36, was caught off guard by the news, saying that doctors had told him he has a small “hole outside” of his heart, causing an irregular heartbeat. Feliciano said he did not believe it to be a life-threatening condition, but it is serious.

“It’s scary, I don't know,” Feliciano said. “I am waiting for the doctors and for them to bring the monitor down here and then more tests.”