Rio Ferdinand's England career looks to be in doubt after he pulled out of the squad for the upcoming World Cup qualifiers against San Marino and Montenegro today.
The reason for the 34-year-old leaving the squad is due to "the detailed pre-planned training and medical programme he must follow," said England manager Roy Hodgson.
The Manchester United defender was called up for the first time since June 2011 and named in the squad for the first time by Hodgson.
Following the call up, Ferdinand's club manager Sir Alex Ferguson expressed concern over his inclusion, saying on Friday: "I was as surprised as anyone when I heard (about the call up).
"I need to speak to the (United) doctor because we prepare Rio Ferdinand in a certain way and there are certain treatments he has to go through.
"He has to make sure he is going to be OK in terms of the number of games he plays.
"We have been doing that for two years and it has worked.
"We have to look at all these things before Rio decides (if he joins up)."
Despite Ferguson's comments, it was confirmed over the weekend that Ferdinand would link up with the squad, yet that decision has now been reversed.
Hodgson revealed that following a meeting with the defender, Ferdinand had withdrawn from the England set-up - with Tottenham defender Steven Caulker, originally in the Under-21 squad, called up as a replacement.
"I was pleased that Rio called and asked to meet with me. It was important to hear from him personally about the way he must manage his body between games," said Hodgson.
"This is not to say he cannot play back-to-back games - he can and has proven so.
"He's out this time due to particular pre-planned details already in place for his programme.
"I must place on record how I was impressed with his commitment to playing for England and I look forward to hopefully selecting him for squads in the future."
Ferdinand himself posted a statement on Facebook which read: "I have withdrawn from the England Squad due to a pre-planned training and medical programme that I must follow.
"It was important for me to be able to speak with Roy face to face and explain the situation, and one thing I made clear was that my passion and commitment to represent my country is as strong as ever.
"It is disappointing that I won't be able to play a part in the upcoming games but I told Roy that I want to continue to be available for England and I look forward to working with him in the future."
The Manchester United defender added on Twitter that he was "gutted".
Despite Hodgson's refusal today to close the door on Ferdinand - any future selections appear remote.
The Manchester United defender's inclusion owed something to Phil Jagielka being sidelined with an ankle injury, Joleon Lescott's bit-part role at Manchester City and question marks over Gary Cahill's form. Hodgson will be hopeful that when future squads are announced he has more options available to him.
Ferdinand's omission from Hodgson's England up until this point has been put down to "footballing reasons", yet it has been impossible for it not to be linked with John Terry.
The Chelsea captain was picked for Euro 2012 while Ferdinand was not, at a time when Terry was facing allegations of racially abusing Rio's brother Anton. Selecting the pair of them had the potential to cause problems in the England camp, and it was Terry who was chosen to remain.
There were also concerns over Ferdinand's relationship with Ashley Cole, who gave evidence on behalf of Terry during his trial. In retaliation, Ferdinand endorsed a tweet which referred to the Chelsea left-back as a 'choc-ice' - a phrase understood to mean someone who is black on the outside but white on the inside. Hodgson was forced to play down the significance of any rift after he named Ferdinand in the squad.
While it appears Hodgson had been able to put those issues to one side as he looked to mastermind victories over San Marino and Montenegro, concerns over Ferdinand's fitness may not be surmountable.