Mako Vunipola will play no part in Saracens’ Premiership play-off defence after his season was ended by injury.
The England prop tore a hamstring in the first half of last Saturday’s Champions Cup final, which Saracens won to conquer Europe for the third time in four years.
Sarries boss Mark McCall described Vunipola’s injury as “significant” - but says he will be fit in good time for the World Cup.
“Mako has torn a hamstring and is waiting to see exactly what’s going to happen but I would very much doubt he’d play again this season,” said McCall, who confirmed that first-choice tighthead Titi Lamositele’s season is also over.
“Mako won’t be out of the World Cup. He will be out for a while though, it is quite a significant injury. Obviously it’s disappointing to lose two players like that. It makes us a little bit vulnerable, to be honest.”
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Vunipola lasted less than half an hour of Saturday’s triumph and last night posted pictures of himself celebrating with teammates on Instagram with the caption, “Little throwback to my best John Terry impression.”
The Londoners finish their regular season campaign at Worcester tomorrow and their selection plans suggest they do not expect to overhaul leaders Exeter, who go into the final round of matches four points clear.
McCall will not field any of the team which beat Leinster in Newcastle - which is probably wise given post-match celebrations lasted into this week.
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But he has held a meeting with his players to remind them that he does not expect a repeat of two years ago when they won Europe then crashed to Premiership semi-final defeat.
“We took our eye of the ball a little bit,” he said. “We weren’t quite as prepared as we should have been for a big match like that. We’ve addressed that. We’ve talked about the regret from two years ago.”
Billy Vunipola and Jamie George, who picked up knocks at St James’ Park, are both “okay”, according to McCall, and will be available for a home semi-final next week, most probably against either Northampton or Harlequins.
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Saints lead Quins by a point in the race for fourth and are understood to have decided against giving Dylan Hartley his first start of the year away at Exeter.
England’s co-captain has not played since December 21 due to what Eddie Jones termed a “grumbly knee”, which required surgery in February.