John Daly has become the latest past champion to withdraw from the 152nd Open.
The 1995 St Andrews champion pulled out of the championship on Friday morning due to a knee injury.
Daly carded an 11-over-par 82 on Thursday at Royal Troon, which was the same score as Ernie Els who also withdrew. Els cited a back injury.
The American, who also won the 1991 PGA Championship, was due to begin his second round at 1:37pm local time (8:37am) alongside amateur Santiago de la Fuente and Aaron Rai.
Daly has struggled with his knees in the past and regularly takes a cart during the PGA Championship and PGA Tour Champions events. He has had surgery on both knees and also has had his left knee replaced in December 2022.
"For me, I've had probably more surgeries probably than Tiger," he said in 2022. "They just keep adding up over the last five years. But I get this metal put in this knee, hell, I got more metal than the Bionic Man does."
The 58-year-old now has just two Opens left before his exemption runs out, with his final appearance in golf's oldest Major set to be at Royal Birkdale in 2026.
The Arkanas native hasn't made the cut in The Open since Royal Lytham and St Annes in 2012 where he was an impressive T18th.
As well as Daly and Els, France's Romain Langasque also withdrew from the tournament. He called it a day after seven holes of round one.
Daly has played 11 events on the PGA Tour Champions this year, with one top-25 finish. His last victory came in May 2017 at the Insperity Invitational, although he did win the PNC Championship with son John Daly II in 2021.