England players Wayne Rooney, Phil Jones and Glen Johnson have withdrawn from the squad for the country's World Cup qualifiers against Moldova and Ukraine through injury, the FA said on Sunday.
Striker Rooney missed Manchester United's 1-0 defeat by Liverpool in the Premier League on Sunday after suffering a head injury in training, club mate Jones was forced off in the first half and Liverpool defender Johnson left Anfield on crutches.
"England have called up Steven Caulker following the withdrawal of three players from Roy Hodgson's squad due to injury," the FA said in a statement.
CardiffCity defender Caulker has one cap to his name, having started and scored against Sweden in November 2012.
England's problems ahead of Friday's match against Moldova and the trip to Ukraine the following Tuesday did not end there as the weekend's Premier League matches also threw up some other doubts.
Daniel Sturridge, who scored the winner after just four minutes at Anfield and was in line to replace Rooney in the England side, will be assessed after saying he had been playing with a thigh injury.
"He has struggled in the last couple of games and we need to think of Liverpool first," Liverpool manager Brendan Rodgers said.
Earlier concern over midfielder Jack Wilshere, who was replaced near the end of the first half of Arsenal's 1-0 win over Tottenham Hotspur, subsided with manager Arsene Wenger saying he had been hit by a stomach bug rather than injury.
"(It is) nothing that will stop him from playing for England," the Arsenal boss told reporters.
England lie second in Group H, trailing Montenegro by two points with a game in hand and only one point ahead of Ukraine.
Image: Roy Hodgson the manager of England keeps an eye on Rickie Lambert and Theo Walcott
Photograph: Alex Livesey/Getty Images