De Kock Steenkamp has been released from his contract at Ospreys after suffering another major injury.
The 28-year-old lock had hip surgery over the weekend and will return home to South Africa to recover.
Steenkamp has managed just two appearances since joining Ospreys from Cape Town-based Stormers in September 2014.
"The way that it has turned out is really frustrating for everybody, really disappointing," he said.
Steenkamp arrived on Welsh soil with a long-term ambition of eventually winning Test honours for Wales under the residency rule.
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But he suffered a serious Achilles tendon injury within days of joining Ospreys that forced him to miss the entire season.
After playing in a pre-season friendly against Saracens, Steenkamp made his competitive in the Pro12 opener at Ulster and then came off the bench the following week against Munster.
But after complaining of discomfort in his hip, tests discovered the need for surgery, and a decision was taken to cancel his contract.
"I had high hopes coming to the Ospreys last year," said Steenkamp, who will return to South Africa in due course.
"It was a new challenge for me, one that I thought would be a good experience, but injury has meant I haven't been able to have an impact."
Andrew Millward, Ospreys general manager, said Steenkamp's loss was a major set-back to their plans for this season.
"De Kock leaves the Ospreys with everyone's best wishes," he said.
"He was signed last year to give a young squad some much needed experience during the periods when we lose our internationals but, unfortunately, was unable to make the desired impact due to injury."