Leone Nakarawa will no longer join Ulster this summer.
The Fiji international had been set to come in as a replacement for Marcell Coetzee in Ulster's pack but the province have confirmed that the move has now been cancelled.
An Ulster Rugby spokesperson said: “We can today confirm that, on receipt of a detailed medical report following an examination by the club at the weekend, Leone Nakarawa will no longer be joining Ulster Rugby for next season.
“This outcome is disappointing for both the player and Ulster Rugby, however, we will continue to build strongly with our preparations for next season. We wish Leone the very best for the future."
Nakarawa has had his fair share of injury issues, having spent 11 months on the sidelines before returning for Glasgow in January.
It is unclear whether or not there will be an alternative arrival at Ulster, although Nick Timoney's progress has somewhat softened the significant blow of Coetzee's departure in the back row. The other current options are Jordi Murphy, Greg Jones, Sean Reidy, Marcus Rea, Matty Rea and emerging talents like David McCann and Ireland U20s' Reuben Crothers.
Nakarawa could also have been utilised at lock but Ulster already have Iain Henderson, Player of the Season Alan O'Connor, Kieran Treadwell, Sam Carter, David O'Connor and currently injured prospect Cormac Izuchukwu to call upon in the second row.
After Ulster initially announced Nakarawa's signature in January, former British and Irish Lion Stephen Ferris heaped praise on the former European Player of the Year.
"He is an awesome player," he said.
"Nakarawa's off-loading skills and his carrying ability will fit perfectly into what Dan McFarland's been trying to build.
"And his off-loading is just outrageous. You can expect the unexpected when he's playing."