Frankie Muniz Breaks Wrist In Ladder Fall, Set To Miss Races

Fans of Frankie Muniz will have to wait to see him get behind the No. 33 truck again ... as the actor-turned-NASCAR driver busted his wrist in a freak accident -- putting him on the sideline "for the next few weeks."

Muniz shared the news on his social media Thursday, saying he fell off the top of a ladder while changing the batteries in his backyard Ring camera ... forcing him out of competition for the foreseeable future.

"While I'm gutted to miss the races, I'm grateful it wasn't worse," Muniz wrote. "I feel for my team, who've poured their hearts into this season, and I'm thankful for @FordPerformance and their unwavering support."

"The doctor estimates a 6-8 week recovery, so I'll be back in the driver's seat as soon as I'm cleared."

Despite being bummed out about the situation, he did find some time to make a joke about it all, telling people to listen to the warning labels on ladders.

"Note to self: heed the ladder warning that says, "Do not sit or stand on top step." In hindsight, a taller ladder would've been smarter."

TMZ Sports caught up with the former "Malcolm in the Middle" star in February after his 10th-place finish in Daytona earlier this year ... and he told us he was "more hungry than ever" to succeed in the sport.

"The only way to earn respect with my fellow racers is to be out there on track, racing against them, racing them clean, and earning it by where I finish."

Unfortunately for the 39-year-old ... time is not on his side this season. Playoffs for the NASCAR Truck Series kick off Saturday afternoon in South Carolina, with only five more events left on the calendar.