West Brom have lost Nacer Chadli to two months with injury.
The 28-year-old pulled up just 15 minutes after coming on as a substitute against Stoke.
Baggies' boss Alan Pardew admits he's been rocked by the news that the £17m midfielder won't be available until March with a hip injury that has restricted him to just four appearances all season.
Pardew said: “That's a bigger blow than the result against Stoke. Nacer is a quality player and he's out for some considerable time.
“Medically, all the boxes were ticked. But we're going to have to be even more cagey about when he comes back."
Meanwhile, Pardew will consider his loan players' futures in the coming weeks.
The Baggies sent 13 of their best academy stars out to other clubs in the summer, but Pardew has recently brought the likes of Jonathan Leko, Rekeem Harper and Kane Wilson back into training.
He's warned the teenagers their personal development could be put on hold while everyone clubs together to get Albion out of the mess they find themselves in.
“We brought the guys on loan back in because I thought it was important I saw their personalities and have a look at what they do on the training ground rather than seeing their little performances on video," explained Pardew. “Some of them are only subs at the moment.
“It's so that I know in January I'm making the right call. And I said to them all when I got them in, unfortunately for you guys the club is in a position where your personal development might have to go to one side for five months.
“Not completely, because we're going to develop them here, but in terms of going out on loan. The club comes first, and they understood that. If I call one or two of them back to boost the squad, it will be to increase our numbers, and not necessarily to be in the starting XI.
“But it may be an opportunity for them at some time to grab a substitute's jersey and grab a first-team place. That's the message I gave them."