Glasgow Warriors duo DTH van der Merwe and Matt Smith will miss the rest of the season with shoulder injuries.
Canada back Van der Merwe, 32, who has 51 Warriors tries, is recovering from surgery and back row Smith will have a shoulder operation later this month.
Smith, 22, featured in last month's win over Ospreys while Van der Merwe last played in the Champions Cup defeat by Saracens.
Warriors resume their Pro14 campaign away to Cardiff Blues next Saturday.
And Dave Rennie's side will take on Saracens again in the Champions Cup late next month.