Southampton forwards Ross Stewart and Kamaldeen Sulemana have been ruled out through injury until January.
Deadline day signing Stewart picked up a muscle injury at Huddersfield on Saturday in just his second substitute appearance for Saints.
Sulemana injured his hamstring in Wednesday's win over Bristol City.
Boss Russell Martin told BBC Radio Solent: "Unfortunately they're both going to be out for quite a while. It's really disappointing - two big losses."
Scotland striker Stewart, 27, missed the start of the campaign with an Achilles injury after a reported £8m move from Sunderland and Martin said: "Ross is hugely disappointing because he's worked so hard to get fully fit. He landed in a really awkward, compromising position late on in the game against Huddersfield.
"We don't expect him this side of Christmas, probably mid to late January all being well. Maybe even later than that. We'll see. he's still being assessed and monitored and seeing a specialist about it - I am heartbroken for Ross, the whole group are. It's not the same injury, which is a bonus.
"There's always a risk when you come back from a long-term injury. We haven't rushed him. Everyone's been in agreement with the plan. Ross has been desperate to play and be back quicker. It's really unfortunate. Hopefully he'll come back fit and firing."
Ghanaian winger Sulemana, 21, came off in the first half at St Mary's and Martin said: "We were hoping it wouldn't be too significant but he's going to be a similar timeline.
"It's really disappointing but that's football and it's an opportunity for someone else. We have a lot of games between now and then to really focus on."