Manchester United boss Sir Alex Ferguson is confident Rio Ferdinand will shake-off his form struggles once he's fully match-fit. Ferguson has conceded it is the first time he can remember Ferdinand going through such extended torment.

"He has not had spells like this since he joined the club," reflected Ferguson. "It is an unusual experience for him but he will get through it I am sure of that."

Ferguson has claimed Ferdinand is now clear of the back injury sustained during last season's Club World Cup in Japan.

The problem did rule him out for six weeks though and is said to be at the bottom of the muscular issues Ferdinand has encountered since.

The injuries are an argument the player's manager dismisses completely, although he does acknowledge Ferdinand's frequent absences are a contributory factor in his present travails.

"Games will help Rio," said Ferguson. "Missing games takes the rhythm away. Getting it back is the challenge now.

"I am sure he has taken the criticism on board. I don't know whether it is over-confidence but there has always been a casual part of Rio's game since he was a kid.

"It has been an advantage to him at times. At others, particularly in his younger days, it was a weakness.

"But along with his development and maturity, it has brought about some outstanding form over quite a long time for us."