Jason Roy is a doubt for the knockout stages of the T20 World Cup after retiring hurt with a calf injury during England's final Super 12s match against South Africa on Saturday night in Sharjah.

Roy had made 20 off 15 balls opening the batting alongside Buttler, when he was called through for a single off the first ball of the fifth over. He pulled up almost straight after setting off at the non-striker's end, hobbling his way through the rest of the run, and also immediately dropped to the ground, throwing his head back in a mix of pain and frustration.

Roy then hobbled off the pitch with support from Tom Curran, one of England's substitutes for the day, and retired hurt, with Moeen Ali coming in at No. 3. He was later seen covering his hands in despair from the dressing room on the TV broadcast, and was hobbling on a crutch on the boundary edge after South Africa completed a ten-run win.

Roy had earlier clutched the same muscle while fielding, after running around to his right from long-on in the final over of South Africa's innings in an attempt to prevent a six from Rassie van der Dussen off Chris Jordan.

"It obviously didn't look great," Eoin Morgan, England's captain, said after the game. "We'll wait until tomorrow to see what his movement is like before we send him for a scan and go from there. We're all hopeful that he comes through in some manner or there's some remedy to get him through one or two games but we need to do what's best for Jason and the team.

"He's unbelievably important. He's a guy who epitomises everything that we are about in the changing room and the way we play. You see how commanding he is at the top of the order… he's as close as we get to surmising how the changing room should play. We're gutted for Jase but also half-hoping that he's OK. For anyone to miss the latter stages of a tournament - particularly when it's been too guys in two games - that does hurt the mood [in the dressing room].

"You got through the names that either aren't here through injury or other reasons: [Jofra] Archer, [Ben] Stokes, Sam Curran, Tymal [Mills] and possibly now Jason. You look back at the times that you've really explored and tried to build a squad, and I'm sitting here thankful that we have done that because we're going to need those guys in the next game and possibly in the final."

England have a back-up batter in their squad in Sam Billings, but it is likely that one of Dawid Malan, Jonny Bairstow or Moeen will move up to open the batting if Roy is ruled out for the knockout stages.

Morgan indicated that England were likely to maintain the same balance to their side, meaning Billings would slot into the middle order. If not, they could bring in an extra seam-bowling allrounder - either Curran or David Willey. James Vince, one of two travelling reserves along with Liam Dawson, would be Roy's likely replacement in the squad.

Morgan said that England had not been "as intense" as they had been in the field, but said that Roy's injury meant they were always up against it in the chase. "We're not going to be at our best every game but we do need to find ways to win," he said. "In the field we weren't as intense as we have been in previous games, just small things we didn't do as neatly or as cleanly as we would have liked.

"I thought with the ball we probably kept them to a reasonable score, in and around par. Obviously when your premium batter goes down, that does hurt you, particularly given the form that he's in. And on the other hand the guys that haven't batted a lot in the tournament came in struck the ball really well, which is a great sign for the semi-final."