DENVER >> Giants ace left-hander Madison Bumgarner was placed on the disabled list for the first time in his big league career today after a dirt bike accident that sent him to a hospital with bruised ribs and a sprained joint in his pitching shoulder.

San Francisco announced Bumgarner’s injury this afternoon, a day after the accident occurred during an off day in Colorado. Manager Bruce Bochy said Bumgarner hit a slippery spot and went down.

Bumgarner drove himself to the hotel, called team head athletic trainer Dave Groeschner and went to the hospital, where doctors ran tests that included X-rays, an MRI and a CT scan.

The plan is for him to remain with the team in Denver, Bochy said. Bumgarner is scheduled to be re-evaluated next week, and the Giants will then have a better idea of a timetable for his return.

“Here’s a young guy, like a lot of us, you think you’re invincible,” Bochy said before the Giants opened a three-game series with the Rockies. “Our focus, it’s on, ‘Let’s get him healthy.’ It’s happened. Let’s get him well and get him back on the mound. Hopefully, it’s a lesson learned … You’ve got to be careful in some of these activities we do.”

This was Bochy’s first day back, too. He missed a two-game series at Kansas City following a heart procedure.

“I feel great. I’m ready to roll. It’s good to be back,” said Bochy, who went in after dealing with an occasional atrial flutter following his workouts. “Good to be with the club and get back into rhythm, I guess you could say. Glad to be back here.”

Before arriving at the ballpark today, Bochy stopped by the room of his injured ace for a visit.

“He’s very remorseful, in talking to him,” Bochy said. “Unfortunately, the accident happened.”

The 27-year-old Bumgarner, the 2014 World Series MVP, is 0-3 with a 3.00 ERA in four 2017 starts.

Bumgarner has received just five total runs of support in his first four starts, including one run or none in three of them — and he homered twice to drive in two of those.

“We ought to just look forward and go out and play hard baseball and hopefully he’ll be back before too long,” catcher Buster Posey said.

Count pitching coach Dave Righetti as not the biggest fan of days off.

“Off days are the freaking worst,” Righetti said. “We don’t get many and when we do guys tend to want to go do those things that they’re missing out on. Things like this do happen, unfortunately.”

Bochy understands.

“If I was there, sure, I wouldn’t have let him on that bike,” Bochy said. “I’m sure looking at it now, Madison wishes he wouldn’t have gotten on it.”

The Bay Area sports scene has become accustomed to fluke injury stories.

Former second baseman and 2000 NL MVP Jeff Kent broke a bone in his left wrist during spring training in 2002 popping wheelies on his motorcycle, initially saying he had injured himself washing his truck. He missed the initial four games that year, when the Giants reached the World Series and lost to the Angels in Game 7.

NBA guard Monta Ellis had signed a $66 million, six-year deal with the Golden State Warriors after he averaged a career-best 20.2 points during the 2007-08 season. He then sustained a serious ankle injury that summer on his motorized scooter and missed most of the season. It cost him a 30-game suspension without pay, because he wasn’t supposed to be riding such a vehicle.

In April 2011, ex-Giants lefty reliever Jeremy Affeldt — who also pitched for Colorado — sprained his right knee and went on the DL after reaching out to catch his then-4-year-old, 60-pound son when the boy jumped off the couch to greet his father.

On Sept. 8 that year, Affeldt sliced his non-throwing hand while separating frozen hamburgers during a barbecue with his family on an off day. The paring knife he was using pushed through a hamburger patty and deep into his hand. Affeldt came within a millimeter of an artery and underwent surgery about eight hours later to repair nerve damage in his pinkie.

San Francisco recalled right-hander Chris Stratton from Triple-A Sacramento to fill the roster spot. Lefty Ty Blach is expected to take Bumgarner’s spot in the rotation.

“Anytime you lose a guy like that in the rotation — as much as he means to the team — that’s tough,” Blach said. “We’re going to come together and we’ll get him healthy and get him back in the rotation.”