Ferdinand's downfall opens door for Cahill

United defender's omission suggests Capello is looking to the future as England meet up ahead of Montenegro test on Friday

In recent times, the partnership at the heart of England's defence has tended to change less regularly than the Prime Minister, or the Governor of the Bank of England. Once in place they stay there for a long time, so what seems like the current phasing out of Rio Ferdinand from that role is not without significance.

Ferdinand has been a mainstay of the England team since around 2001 when he made the position alongside Sol Campbell his own and kept it through injury, an eight-month ban imposed by the Football Association, two World Cups, five qualifying campaigns and the one occasion when he was dropped by Sven Goran Eriksson in October 2005.

Campbell eventually lost his place to John Terry after Ferdinand came back from his ban for a missed drugs test in 2003. But suddenly it sounds like the bell is also tolling for Ferdinand too, this week left out of the squad to face Montenegro on Friday, despite having featured in the last three games for Manchester United.

It was his most recent role, as a substitute for the Norwich City game, which set the alarm bells off in the Fabio Capello camp. Ferdinand played against Stoke City 11 days ago when he was beaten by Peter Crouch for the equaliser. Against Basel at Old Trafford, Capello's assistant Franco Baldini watched a shaky performance alongside Phil Jones as United conceded three to the Swiss team.

On Saturday against Norwich he was on the bench behind Jones and Jonny Evans and the feeling in the England camp was that if Ferguson was not prepared to start Ferdinand, then why should they pick him ahead of the 19-year-old Englishman who is now doing his job?

As ever with Ferdinand and United it is difficult to tell the difference between whether the player is being rested to manage long-term injury problems or simply left out because there are better options. He was left out of the England squad to face Bulgaria and Wales last month, but then he had missed games for United with an injury picked up against West Bromwich Albion on the first day of the season.

Ferdinand will be 33 next month and made his debut in November 1997, a remarkable 14 years ago. Although 81 caps is not as high a return as could have been expected for having spanned such a significant period, that is a lot longer than most last in international football. No one, however, goes on for ever and Ferdinand appeared to refer to his omission yesterday on Twitter when he joked about training with his young son's team... "if selected".

After the disappointment of injuring his knee in the first England training session at the World Cup in South Africa last year, Ferdinand has played just three times for his country and only one of those has been a Euro 2012 qualifier. In the meantime Capello took the captaincy away from him in an episode that could not have been more chaotic.

The message from the Capello camp is emphatically that they are not holding Ferdinand's unwillingness to talk to Capello at Old Trafford in the directors' box as a factor in his most recent omission from the squad. It is said to be purely down to doubts about Ferdinand's form and fitness.

It means that among the current defenders it will be Gary Cahill, of Bolton Wanderers, who is favourite to start alongside Terry in Podgorica on Friday. Cahill's Bolton are bottom of the Premier League and have conceded 21 goals this season but Capello's feeling is that Cahill did well enough against Bulgaria and Wales to warrant a place.

The most likely threat to Cahill, and Terry in the long term, is Jones, even if he did show signs of wobbling against Basel after a strong start to his United career. With Glen Johnson and Chris Smalling injured, Jones is a possibility to start the game at right-back. Phil Jagielka also gives the England manager that option and could adapt to the position if necessary, with Spurs' Kyle Walker and Manchester City's Micah Richards also in the squad.

There are no injuries in the squad, which met up yesterday, and all of them are expected to train this morning at Arsenal's London Colney headquarters. Bobby Zamora will be back among the squad for the first time, picked by Capello because the England manager believes the Fulham striker is the kind of player who can connect the play well and create chances for other strikers and midfielders.

For Cahill and Jones it represents a major opportunity to lay down a marker and make the position alongside Terry their own. Reputations can be made quickly and there is the feeling that this time a rare place has opened up in the middle of the England defence.

Centre of attention: Will Cahill or Jones partner Terry?

Gary Cahill: Age 25, Caps 5, Goals 1

Rio Ferdinand: Age 32, Caps 81, Goals 3

John Terry: Age 30, Caps 70, Goals 6

Phil Jones: Age 19, Caps 0, Goals 0