England will try to identify “an X-factor player” as a replacement for Reece Topley, who has been formally ruled out of the rest of the World Cup after scans confirmed a fracture in his left index finger.

Topley was struck while fielding a ball off his own bowling in England’s 229-run defeat to South Africa and could not complete his fourth over. He returned to bowl five further overs with his fingers taped together but could not bat, and the ECB confirmed on Sunday evening that his World Cup is over.

England are yet to determine which player will replace Topley in their 15-man squad but confirmed on Saturday night that Jofra Archer would not be considered for selection. Archer is recovering from an elbow stress fracture and joined England’s squad in Mumbai last week as part of his rehabilitation.

He was initially described as a travelling reserve but Matthew Mott, England’s coach, clarified that he was not in the picture to replace Topley: “He’s not going to be able to play a part in the end of this campaign,” Mott said. He has since left India, though the ECB insist that his rehabilitation is progressing as expected.

Brydon Carse, the Durham fast bowler, made one appearance in England’s ODI series against New Zealand last month and also featured in the second-string side that played Ireland, and as such is the favourite to replace Topley in the squad. But Mott stressed that England will also consider alternative options.

“Good question,” Mott said, asked if England would replace Topley with another seamer. “We’ll have to sit down and have a look at that. We’ll have to look at the upcoming games. If there is an X-factor player we can look at… that’s why we were very keen not to name the replacements and reserves, and it leaves a bit of an open mind for what we might go with.”

England are unlikely to qualify for the semi-finals unless they win all five of their remaining fixtures and change their balance significantly on Saturday. As such, they may be tempted to bring in a batter – like Jason Roy or Ben Duckett – or a spin-bowling allrounder such as Liam Dawson, Will Jacks or Rehan Ahmed. Luke Wood is also a possible like-for-like replacement.

Topley left the field with a ball remaining in his fourth over in England’s 229-run defeat to South Africa on Saturday night. He was struck on the index finger of his bowling hand while attempting to stop a straight drive from Rassie van der Dussen, and, after bowling another delivery, was unable to complete his over.

He later returned to bowl with his index and middle fingers strapped together, dismissing both Aiden Markram and David Miller after removing Quinton de Kock with the second ball of the match. But, like the rest of England’s attack, Topley was hammered at the death by Heinrich Klaasen and Marco Jansen, conceding 45 runs across his final two overs to finish with 3 for 88 from 8.5 overs.

He did not come out to bat in England’s innings and was sent for scans in Mumbai, which confirmed the medical team’s suspicions of a fracture. “Topley will return to the UK in the next 24 hours,” the ECB said in a statement. “He will work closely with the England and Surrey medical teams in respect of his rehabilitation.”

Despite being left out for their first match of the tournament against New Zealand, Topley leaves the World Cup as England’s leading wicket-taker, with eight in his three appearances. It is the second consecutive ICC event he has left early, after he was ruled out on the eve of last year’s T20 World Cup with a freak ankle injury, suffered when treading on a boundary sponge.