San Francisco 49ers coach Jim Harbaugh will be spending Thursday night in a hospital undergoing a “minor procedure” after he was discovered to have an irregular heartbeat.

According to ESPN News, the procedure is expected to be extremely minor and Harbaugh should return to 49ers headquarters sometime Friday.

The procedure is "not a major cause of concern; it's more precautionary,” according to an unnamed source that spoke with ESPN. Reportedly, the coach began experiencing chest pains sometime on Wednesday.

Team spokesman Bob Lange told ESPN the procedure was not the result of an unexpected incident at the 49ers’ facility. Rather, Harbaugh had made an appointment with doctors on Wednesday night after leaving practice early when he felt ill.

The San Francisco 49ers camp hopes Harbaugh will be back in full capacity by Monday, when the team plays the Chicago Bears. The game is expected to be particularly tough, as the 49ers lead the NFC West while the Bears lead the NFC North.

"It's one of those things that, like coach Harbaugh always tells us, he's tougher than a $2 steak," 49ers linebacker Patrick Willis said. "We know he's going to be all right. We know we have a bunch of great coaches here that keep everything on track, and we're going to practice today as if he was here.”

Dashon Golson, a 49ers safety, said he expects the treatment to be completely routine as Harbaugh showed no serious signs of distress over the past two days. 

"He was pretty good. We were slapping hands and talking yesterday,” Goldson told ESPN. "I didn't see anything. He showed no emotions. He didn't show anything like that."