Leinster centre Robbie Henshaw is expected to miss the start of the Pro12 season due to the pectoral muscle injury he sustained playing for the British and Irish Lions.
Henshaw's tour came to an abrupt end after he tore the muscle as the Lions were held to a 31-31 draw by the Hurricanes ahead of the second Test.
The Ireland international flew home after Saturday's second Test and Lions head of medicine Dr Eanna Falvey has revealed the extent of Henshaw's problem.
"That was a pretty significant injury, he's completely avulsed the muscle from the bone which requires to be re-attached to the bone," he said.
"That's usually about a 16-week recovery. He may do slightly better, but that's probably what we're looking at."
Sixteen weeks on the sidelines would mean Henshaw would not be ready to return until October, with Leinster's 2017-18 season kicking off in September.