Leicester full-back Telusa Veainu suffered a double fracture to his jaw during Saturday's European Champions Cup defeat against Munster.
The Tigers said that Veainu was due to undergo surgery on Monday.
The Tonga international was hurt following a collision with Munster wing Andrew Conway early in the second half at Thomond Park. Conway also went off.
"It is very disappointing," Leicester head coach Matt O'Connor told the club's official website, while also confirming an expected absence of several months for Veainu.
"I said immediately after the game there is a duty of care for the ball-carrier, and Telusa has been seriously injured after a collision with an opposition's shoulder and head which will make him miss a key part of the season.
"We look forward to his full recovery and getting him back on the field in due course."
Veainu has been in blistering form this season, and Leicester will miss his considerable attacking threat ahead of next Sunday's Munster return meeting at Welford Road, which is followed by Aviva Premiership appointments with Saracens, Exeter and London Irish.
Leicester currently stand third in Champions Cup Pool Four, five points behind leaders Munster halfway through the group stage.
Five pool winners and the best three runners-up will secure quarter-final places.
Source: PA
