Tuilagi's season is over
The 25-year-old – who had already been on the sidelines for two months of this season with a groin injury – suffered the latest blow in his side's 12-16 Premiership loss to champions Saracens on Sunday.
He had been called up for a pre-Six Nations training camp with the Grand Slam holders due to take place next week but withdrew on Tuesday.
"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 Aaron 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 Samoan-born back has been bedevilled by injury over the past few years and managed just one appearance as a replacement for England last year.
He had only been recalled to the squad in 2016 after a two-year hiatus due to injuries and disciplinary problems.
Mauger, who is in sole charge of The Tigers since long-serving Director of Rugby Richard Cockerill was sacked on Monday, says he believes Tuilagi will come back stronger despite the latest blow.
"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," said Mauger.
Agence France-Presse
