Harlequins and Italy centre Michele Campagnaro will miss the Six Nations and the rest of the club season following knee surgery.
The 26-year-old was injured early in Quins’ 30-30 Premiership draw with Leicester at Twickenham on 28 December.
Campagnaro joins fellow Harlequins centres James Lang, Ben Tapuai and Francis Saili on the treatment table.
Ex-Exeter and Wasps player Campagnaro joined Quins this season after playing for Italy at the World Cup.
Quins now have a lengthy injury list of 15 senior players currently unavailable for selection, including five centres and four hookers.
Former England captain Chris Robshaw will miss the visit of Clermont on Saturday with a head injury sustained against Bath in the previous European Champions Cup round.
And back row Tom Lawday and winger Travis Ismael are both recovering from hamstring tears.
“This is not only freakish, but reveals the hidden cost of injury in terms of training pedagogy and numbers,” head of rugby Paul Gustard said.