DWAYNE 'THE ROCK' JOHNSON had to cut his honeymoon short to fill in for Kevin Hart on 'The Kelly Clarkson Show'.

The 47-year-old actor - who tied the knot with his wife Lauren Hashian last month - agreed to leave the romantic holiday in Hanalei Bay, Hawaii, in order to step in for his 'Jumanji' co star on the debut of the 'Stronger' hitmaker's new show at the last minute after he injured his back in a car crash last week.

Speaking in a promotional clip for the programme, which will air on September 9, Kelly said she was so grateful to The Rock after he ''stepped the heck up'' but she's convinced his wife ''probably hates'' her now.

Kevin was scheduled to be the first guest on the show, but he threw things into a spin last week when he was involved in a serious car accident in Malibu, California, which left him needing surgery on his spine.

The operation went well and he's expected to be discharged from hospital later this week, but he'll need ''extensive therapy'' to help repair his injuries.

The 'Ride Along' star was in the car with two other people - driver Jared Black and his fiancee Rebecca Broxterman - when his Plymouth Barracuda veered off the highway and ended up in a gully about 10 feet off the road.

Both Kevin and Jared were taken to hospital after sustaining ''major back injuries'', but Rebecca did not need medical treatment.

Shortly after his surgery, Kevin's wife Eniko Parrish, with whom he has 22-month-old son Kenzo, reassured fans that he was doing ''great'' and that he's going to be ''just fine'' after the accident.

Kevin, 40, had previously taken to social media over the weekend to post a video of himself driving the classic car, as someone yelled at him for laying down too much rubber on the street as he spun out his tires.

The 'Get Hard' star - who also has Heaven, 14, and Hendrix, 11, with his ex-wife Torrei Hart - bought the car back in July as a 40th birthday gift to himself.