Cahill ruled out of Euros with fractured jaw
The only glimmer of good news for a squad facing a deepening injury crisis was fellow defender and Cahill's Chelsea team-mate John Terry being given the all-clear after checks on his hamstring.
The Football Association said Cahill had been withdrawn from the squad for the tournament in Poland and Ukraine that starts on Friday.
"The Chelsea defender has two fractures of his jaw, one either side. The England medical team have been in close contact overnight with Cahill's club doctors who will treat him moving forward," it said in a statement.
Liverpool defender Martin Kelly will join the squad, subject to the agreement of UEFA's medical team, after training with the other players last week and travelling to Norway with them for the first friendly of manager Roy Hodgson's reign.
Cahill was injured just 17 minutes into Saturday's friendly at Wembley when he was shoved in the back and sent clattering into his own goalkeeper Joe Hart by Belgium striker Dries Mertens.
The FA had feared a broken jaw but hopes appeared to have risen on Sunday when their director of football development Trevor Brooking indicated the player could have escaped a serious injury.
"At the moment we are still hoping that the 23 [squad members] might stay intact," he had told BBC radio before the bad news arrived.
Mertens issued an apology to Cahill on his Twitter page.
"I sincerely apologize for the harm I've cost to Cahill. When in the heat of the moment, you often don't think about the consequences," he said.
The FA said former captain Terry, who collected his 73rd cap on Saturday, had been cleared after a scan and would be reassessed on Tuesday when the squad regroup.
England play France in their opening Group D Euro 2012 match in Donetsk, Ukraine, on June 11 and have already lost experienced midfielders Frank Lampard, Gareth Barry and reserve goalkeeper John Ruddy from the original squad.
Captain Steven Gerrard limped off with cramp on Saturday while goal-scorer Danny Welbeck was withdrawn to protect him from a stomach reaction to antibiotics.
England go into the tournament with expectations lower than they have been in decades and with striker Wayne Rooney suspended for the first two group matches.