DUBLIN, Ohio -- Collin Morikawa withdrew from the final round of the Memorial on Sunday because of back spasms, keeping him from a chance to win for a second time at Muirfield Village.

Morikawa had shot 68 in the third round and was 2 shots out of the lead. He said he was doing preround exercises when a muscle in his lower back gave out.

"We were doing some like reflex stuff, trying to reach down and try to pick something up like quick and low. Went after it weird," he said. "Literally have never had this in my life. I've hurt my back briefly before, but like nothing has been this bad, especially never warming up."

He said he tried hitting about 10 balls on the range and he hit a clunky 9-iron that went only about 95 yards. He realized that wouldn't work at Muirfield Village.

Morikawa won the Workday Charity Open at Muirfield Village in 2020 when it was held a week before the Memorial, replacing the Canadian Open during the COVID-19 pandemic.

Morikawa said he wasn't overly worried about the recovery and will rest ahead of the U.S. Open, which is June 15-18 at Los Angeles Country Club.