Manu Tuilagi has been ruled out for the rest of the season with the anterior cruciate ligament [ACL] injury he picked up while on Leicester duty against Saracens last weekend.
Tuilagi lasted just nine minutes until he was forced off with a knee injury after being hauled down following one of his bulldozing runs.
Aaron Mauger, the Tigers' interim coach, confirmed on Wednesday that Tuilagi will now miss the rest of the season due to ligament damage.
"Unfortunately Manu sustained an ACL injury in the game on Sunday that's going to put him out for the rest of the season," said Leicester coach Mauger.
"It's looking like a six-month recovery which is devastating for the bloke, he's worked so hard to get back to where he is.
"He's absolutely gutted, but we've got a good support team around him, we'll put a good plan in place and we'll see him back on the field early next season."
The news comes as a bitter blow for Tuilagi who has started just 11 Premiership matches across the last three campaigns.
He will now definitely miss the Six Nations and is unlikely to be fit in time for the British & Irish Lions tour of New Zealand.
Asked if Tuilagi can ever hit back to top form, Mauger replied: "Oh absolutely; Manu's started to show those signs in the last couple of weeks that's he's been in probably the best space that he's ever been in.
"We're really proud of the growth we've seen in him as a person.
"He was starting to get his explosive power and speed back and is really starting to understand the game better as well.
"He's starting to become a more complete footballer which is a great space for him to be in."
The Press Association contributed to this report