We won’t speculate on this (too much), but we will point out that an irregular heartbeat is often caused by stress.

On Thursday, San Francisco 49ers coach Jim Harbaugh was sent to a hospital when doctors discovered he had an irregular heartbeat. But no matter, after having what was described as “not a major concern” and “precautionary” procedure done at Stanford Hospital, the team plans to have Harbaugh back at practice on Friday, according to ESPN.

On Wednesday, Harbaugh reportedly began feeling ill and having chest pains. That evening, he went to see doctors, who advised him to have the undisclosed procedure performed. According to players, however, everything seemed fine at Wednesday’s practice.

“He was pretty good. We were slapping hands and talking yesterday,” said 49ers safety Dashon Goldson. “I didn’t see anything. He showed no emotions. He didn’t show anything like that.”

Harbaugh’s San Francisco squad sits at 6-2-1, atop the NFC West and considered a major Super Bowl threat.