As Charlotte Bobcats coach Steve Clifford was checking himself into a local hospital Thursday night, worried about sudden chest pains, Denver Broncos coach John Fox was about to be released from another Charlotte hospital.

Charlotte had become the unfortunate epicenter of a recent trend: Head coaches in their 50s in major American pro sports who are experiencing a health crisis. There have been three of them in the past week.

Clifford, 52, was No.3. He had a procedure Friday morning where doctors inserted two stents in his heart. By mid-afternoon, Clifford was talking with Bobcats associate head coach Patrick Ewing, who coached in his place Friday night in a 101-91 home loss to the New York Knicks.

“He sounds great,” Ewing said before the Bobcats and Knicks tipped off. “He was joking with me. He’s chomping at the bit to get out (of the hospital).”

Fox, 58, who was the Panthers’ coach for nine years and still has an offseason home in Charlotte, had his aortic valve replaced Monday. He will miss Sunday’s Broncos game and an undetermined number of others before returning this season.

It is unclear when Clifford will be back.

“He’s still in the hospital,” Ewing said. “So he’s not going to be here (Friday or Saturday), but hopefully be back on Sunday.”

I hope the Bobcats, who next play at home against Atlanta on Monday before going on a two-game road trip, will be overly careful with Clifford. They might need to save him from himself and keep him from hustling back the way he always wants his players to do on defense.

This is scary stuff. Clifford has had a fine start in his rookie season as Bobcats coach, going 3-2 in his first five games before Friday, and it’s natural for him to want to return quickly. “Cliff” is a pleasant man and one of those guys who is completely wedded to his job.

But we’re talking about life, not mere games, in the cases of Clifford, Fox and Houston Texans coach Gary Kubiak, 52, who suffered a very public mini-stroke at halftime of Houston’s game against Indianapolis on Sunday night.