New Zealand batsman Brendon McCullum has been ruled out of Middlesex's T20 Blast quarter-final against Northamptonshire on Tuesday.
The 34-year-old has a long-standing back injury which requires surgery.
Former Black Caps skipper McCullum recently had a stint playing in the Caribbean Premier League for Trinbago Knight Riders.
He scored 132 runs at an average of 33 in six appearances for Middlesex during the group stage of the tournament.
"Brendon felt he could not do himself justice and did not want to risk letting the team down in such an important game," Middlesex managing director of cricket Angus Fraser said.
"He has been having regular injections and dosing up on pain killers for some time just to get by, which is not particularly good for you."
Meanwhile, Ireland batsman Paul Stirling has signed a new contract which will keep him at Lord's until the end of the 2019 season.