Toulon's Springbok wing Bryan Habana will miss up to three months after an injury sustained against Exeter Chiefs was found to be worse than first thought.
South Africa international Habana made his Heineken Cup debut for the French Top 14 club at Sandy Park last weekend.
But although Jonny Wilkinson's men left Devon with a 14-9 victory, Habana was forced off the field in the first half with a thigh injury after pulling up sharply when he tried to accelerate.
Although the initial diagnosis suggested Habana would miss three weeks, Toulon coach Bernard Laporte confirmed yesterday that surgery will be required.
Habana will undergo an operation next week and will be out for at least two months. He was always likely to miss this weekend's return fixture against the Chiefs at Stade Felix Mayol on Saturday.
However, he now looks certain to miss the remaining pool stages games in the Heineken Cup next month as well as Top 14 games against Montpellier and Racing Metro.
The reigning champions suffered further setbacks with Habana's fellow South Africans Bakkies Botha and Craig Burden also likely to miss game-time over the coming weeks.
Lock Botha, a World Cup winner alongside Habana in 2007, is a doubt for Saturday's match having had 12 stitches in a facial wound, while hooker Burden faces a much longer spell out as a result of a torn bicep.