Kilmarnock defender Mark Connolly has been ruled out for the rest of the season and manager Gary Locke fears losing Jamie Hamill as well.
It has been confirmed that Connolly broke his collarbone during the 3-3 draw with Inverness Caledonian Thistle.
And midfielder Hamill had surgery on a troublesome ankle on Thursday.
"My worst fear is that he misses the rest of the season, but hopefully it will be news that he will only be out for five or six weeks," said Locke.
Connolly, 23, had joined Kilmarnock after leaving Crawley Town, while 28-year-old Hamill is in his second spell at Rugby Park after spending three years with Hearts.
A third summer signing, Michael Ngoo, will not play again this season after a tackle by Celtic's Virgil van Dijk ended his campaign.
Meanwhile, fellow striker Lee Miller is only just returning from six weeks out with knee problems.
"Mark is also out for the remainder of the campaign and that is really disappointing because he's had a fantastic season," added Locke.
"These things are definitely not what we need at this point in the season, but there is no point sitting moaning about it.
"These guys are injured and out of action, so we just need to concentrate on the boys who are available."