London Irish centre Setaimata Sa will not play again this season because of injury - having made just one appearance for the Exiles.
The Samoa international was signed from Catalans Dragons last year but his arrival was delayed until March because of issues with his visa and injuries.
He finally touched down in Berkshire and made a promising debut against Northampton - but a knee problem means he will not be seen again this season.
London Irish medical staff want to fix a minor problem now and have Sa fighting fit for the start of next season.
Sa tweeted: "Minor surgery needed so I'm good to go for pre-season and be hundred percent for next season. Could of carried on but medics' choice."