San Francisco 49ers head coach Jim Harbaugh had a "minor procedure" on his heart Thursday and was sent to the hospital from the team facility.

According to ESPN.com, a source said that Harbaugh felt chest pain on Wednesday and that the issue is "not a major cause of concern; it's more precautionary."

Harbaugh was with the team on Thursday, but left practice after doctors recommended he should go home. Harbaugh later had the procedure done at Stanford Hospital. He is expected to return to practice on Friday without any issues.

"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 to ESPN.com. "We know he's going to be alright. 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."

The 49ers were preparing for their Monday nigh game against the first-place Chicago Bears at Candlestick Park, who are 7-1 and leading the NFC North.

The team released an announcement on Thursday, according to Yahoo Sports:

"Coach Harbaugh is not at the facility today under doctor's orders. He is having a minor procedure done at Stanford Hospital today for an irregular heartbeat. We anticipate that he will be back at the facility tomorrow, but do not have any further information to share at this time."

Although the news took players by surprise, they expect Harbaugh to be back to normal on Friday.

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

The statement also said that assistant head coach and special teams coordinator Brad Seely led the team during practice on Thursday and ran afternoon meetings.

"He seemed fine to me. He actually sat right behind me in meetings. He seemed fine. I didn't know anything was wrong. But like I said, we know he's going to be alright," said Willis.

Harbaugh won NFL Coach of the Year last season after leading the 49ers to the NFC West division title with a 13-3 record. The team beat the New Orleans Saints in the playoffs before falling to the Super Bowl champion New York Giants in the NFC Championship game.

On Thursday night, Seattle Seahawks head coach Pete Carroll, who coached against Harbaugh at Stanford while he was at USC, sent out his best wishes on Twitter.

"Sending out best wishes to Jim Harbaugh for a quick recovery... Get well soon, we gotta alotta ball games left"

The 49ers have also been dealing with Alex Smith's concussion, which he sustained in last week's tie against the St. Louis Rams. If he can't start on Monday night, rookie Colin Kaepernick will take his place. Kaepernick passed for 117 yards while completing 11-of-17 passes in relief of Smith.

"Rather than speculate, we'll let it play out," Harbaugh said of Smith earlier in the week. "There's a progression and evaluations that have to be gone through before we'll really know anyway. ... He's doing much better, had a good night sleep last night, symptoms were positive today. He'll be visiting with the neurologist later this afternoon. That will be the next step."

Smith left the game in the second quarter and experienced blurred vision.