Sir Alex Ferguson has admitted that he is concerned about a lack of defensive back up in the Manchester United squad, with the Scot worrying about pre-season injuries to some of his most promising players.

Ferguson is currently in the midst of some big transfer deals, with the Red Devils having just lost out on Lucas Moura, but still hoping to land Robin van Persie from Premier League rivals Arsenal before deadline day passes.

But United appear to have another problem looming alongside their chase for a striker and midfielder, with Ferguson revealing that defensively the club may be lacking at the start of the season as well.

"[Jonny] Evans is recovering from an operation," he told the United website. "[Chris] Smalling is out for three months. [Phil] Jones got a muscle injury in his back and was sent home from Norway.

"So the area we're concerned about is centre-back. Evans won't be ready for the start of the season. He won't be far away but he won't be ready.

Phil Jones
Phil Jones has already suffered an injury before the season has started.

"Smalling is out and I can't give you an update with Jones because we've not fully diagnosed that. But Michael Carrick was absolutely brilliant [in Sweden] with his passing the ball and his interceptions. He was fantastic."

For United, the task at hand is currently trying to get hold of van Persie to build an unstoppable striking force, with Ferguson admitting last night that the club were still interested despite Arsenal's unwillingness to do business.

But now Ferguson looks to need a defender as well, spelling out a big month for the manager as deadline day edges closer.

Last summer, United were typically early in their transfer dealings, shoring up Ashley Young, David de Gea and Phil Jones before the end of June.

Ferguson kept quiet over the trio until the deals were done, but this summer is shaping up to be very different from the last, with the manager being particularly open about possible transfers within the club.

Whether this tactic will work or not remains to be seen, but Ferguson is being uncharacteristically public about his admiration for van Persie as he works to coax the prolific striker from the Gunners' grasp.