Saracens scrum-half Ben Spencer is set to be named on the bench in Saturday's Rugby World Cup final after being called up to the England squad as an injury replacement for Willi Heinz.

Heinz suffered a hamstring injury after coming on as a 63rd-minute replacement for Ben Youngs in the semi-final win over New Zealand.

Heinz will remain with the squad until the end of the tournament.

Spencer, 27, who has won three caps, will arrive in Japan on Monday.

Coach Eddie Jones named only two specialist scrum-halves in his initial 31-man squad, leaving him short of cover at nine.

"Picking only two scrum-halves was one of Jones' rolls of the dice," said former England fly-half and BBC Radio 5 Live analyst Paul Grayson.

"It takes six, seven, eight days to get over the jet lag, even if I am sure Ben Spencer is travelling in the right part of the plane.

"Could he have been better prepared by being involved with the squad more often? It's certainly not ideal preparation."

England have several other injury concerns for the meeting with either Wales or South Africa, with Owen Farrell and Jonny May nursing dead legs, while prop Kyle Sinckler has a calf issue.

Anthony Watson was able to finish the win over the All Blacks but he received regular treatment during the game for an unspecified knock.

Spencer, who helped Saracens secure a Premiership-European Cup double this year, made his most recent appearance for England in March's 38-38 draw against Scotland.

New Zealand famously called up fly-half Stephen Donald, who had been left out of Graham Henry's squad, late in their 2011 campaign after injuries to Dan Carter and Colin Slade.

Donald, who had missed Henry's initial phone call because he was fishing for whitebait in rural New Zealand, was brought on in the final after Aaron Cruden succumbed to an injury in the 34th minute. He kicked the decisive penalty in a ill-fitting shirt, later admitting he had put on 5kg in extra weight assuming he would not be involved.