England skipper Eoin Morgan admitted the prospect of losing injured opener Jason Roy for the Twenty World Cup semi-final "really hurts the mood" in the team.
Roy, 31, suffered a calf injury and collapsed to the ground while chasing a quick run in Saturday's 10-run loss to South Africa.
Despite the defeat, England, along with Australia, made the semi-finals on net run-rate while South Africa were eliminated.
"We are gutted for Jason, but also sort of half-hoping that he's okay," said Morgan who also saw fast bowler Tymal Mills limp out of the tournament earlier this week.
"For anybody to miss the latter stages of a tournament, particularly it's been two guys and two games, that does hurt the mood."
South Africa posted 189 for two with Rassie van der Dussen hitting an unbeaten 94 but needed to limit England to fewer than 131 runs to edge Australia on run-rate for a semi-final spot.
Dawid Malan, who made 33, and Liam Livingstone, who hit 28, kept England in the hunt after Roy retired hurt for 20.
But a last over hat-trick by Kagiso Rabada made England finish on 178-9.
England had come into the tournament without stars Ben Stokes and Jofra Archer.
Morgan said the team has got enough back up to deal with injuries and pull outs.
"Like you go through the names that either aren't here through injury or other reasons, so you go through Archer, Stokes, Sam Curran, Ben (Foakes), Tymal and now possibly Jason," said Morgan.
"You look back at the times that you have really explored and tried to build a bigger squad, and I'm sitting here thankful that we have actually done that because we are going need those guys possibly in the next game or the final."
Roy has made 123 runs at the World Cup with a best of 61.
He has 1,316 runs in the format with seven half-centuries since his 2008 debut.
Morgan, who made 17 and was one of Rabada's hat-trick wickets, said he is yet to watch any match of his possible opponents.
"So as prep for every game, I'll go through strengths and weaknesses of oppositions, I'll watch relevant games," he said.
"So I haven't watched a lot from the other group. So I will do over the next coming days. Let somebody else worry about it."
England are seeking to become double world champions after Morgan's team beat New Zealand in the 50-over World Cup final in 2019.