Ferdinand missed out on the England captaincy this week when Fabio Capello plumped for John Terry in the battle of the defenders.

Even though the decision came as a surprise to most observers - and the bookmakers, who made the United man favourite to land the role - Ferguson cannot believe there was much in it.

In the end, he felt Terry's long-term experience as a captain at Chelsea, compared to Ferdinand's position as United's number three behind Gary Neville and Ryan Giggs was the decisive factor.

And while there is no immediate end in sight to that situation, Ferguson has assured the Londoner he will eventually get the job on a full-time basis.

"John Terry has been captain of Chelsea for quite a while. That must have been an advantage," said Ferguson.

"The difference here is that I operate my captains on seniority.

"In the long-term Rio will be captain of Manchester United, there is no question about that. It is a position we are very comfortable with that.

"His leadership qualities have improved tremendously over the last couple of years and his ability is there for all to see."

Although Ferdinand performed no better or worse than any of his underperforming England team-mates at Wembley on Wednesday night, there is a fear the 29-year-old will suffer a hangover from his disappointment.

The Peckham-born star has never made any secret of his desire to lead his country at some point in his career and given Terry is two years younger, there must now be a good chance he will never lead his country permanently.

But Ferguson does not believe Ferdinand should dwell on the setback.

"I don't think anyone was actually nailed on for it," said the United boss.

"It was always a flip of the coin between Rio or John Terry.

"At Rio's age I don't think we need to worry about the effect of what happened.

"He has proved himself a great centre-back.

"But it was the manager's choice and he has chosen John Terry, Rio just has to get on with it. It is as simple as that."

Ferdinand will be part of an injury-ravaged United side who tackle Portsmouth at Fratton Park on Monday, looking for a victory following last week's dismal home draw with Newcastle.

Ferguson does have a couple of extra attacking options now Carlos Tevez has returned to duty after a family bereavement and Anderson's Olympic commitments with Brazil are over.

However, the loss of Michael Carrick for three weeks is a blow and while Cristiano Ronaldo has been pictured jogging at United's Carrington training base, he will not be fit until October.

At least fears of a long-term problem for Ryan Giggs, who limped out of Sunday's game with a hamstring tweak, have proved unfounded.

Wayne Rooney should be fitter as well. The striker was forced to carry much of the responsibility for United's attack on his shoulders last week despite only returning from a two-week absence after picking up a virus in Nigeria.

His appearance for England in their midweek draw with the Czech Republic at Wembley on Wednesday should have sharpened him up even further and Ferguson is looking for the return of Rooney's selfish streak.

Both Ferguson and Capello have claimed the 22-year-old expends too much energy doing jobs he does not necessarily need to do, although the United boss admitted there are far worse crimes to commit.

"I have no problems with Wayne Rooney at all," he said.

"Unselfishness is maybe not the biggest crime to have as a football.

"It shows qualities of teamwork and a general nature which is terrific to see in footballers.

"We are in an era of individual appreciation. Earrings, tattoos, goals, the need to be seen.

"It is refreshing someone is prepared to sacrifice that for the team effort."