World Cup 2010 - Upson to start against Slovenia
The England manager told the BBC that the West Ham player will start alongside John Terry in central defence for the crucial Group C match in Port Elizabeth.
With Ledley King still injured and Jamie Carragher suspended, the Italian was faced with a choice between Upson and the uncapped Michael Dawson for the role - and he has chosen to give Upson his 20th England cap.
"Upson will play because he always played with John Terry and I probably will change some others," Capello said.
King and Michael Carrick both sat out training on Monday as England prepared for the must-win match.
Manchester United midfielder Carrick sustained an ankle knock on Sunday and was still unable to train on Monday, but he is expected to be available for Wednesday's game.
Carrick is tipped as a possible starter if Capello switches to a 4-5-1 formation and retains Steven Gerrard on the left flank, but if Joe Cole plays on the left then Gerrard will partner Gareth Barry and Frank Lampard in central midfield.
Spurs defender King also sat out training as he continued his recovery from the groin injury picked up in England's 1-1 draw with the USA.