Aaron Finch has returned to his native Australia to recover from a broken foot.
The 28-year-old suffered the injury during a recent Twenty20 outing for the Yorkshire Vikings against the Durham Jets.
He had been contracted to Headingley until the end of the season, but the Aussie T20 captain has now travelled to Melbourne to see a specialist.
"That's the end of the season for Aaron, as far as Yorkshire is concerned," director of cricket Martyn Moxon told the club's official website.
"Scans have revealed that he has fractured the fifth metatarsal in his right foot. He will now see a specialist in Melbourne. It is a great disappointment for Aaron and the club and we wish him a speedy recovery."
Moxon also confirmed that the club have already opened discussions to extend Glenn Maxwell's stay as cover for Finch.