Manchester United's record-breaking addition of Angel di Maria has been met with dismay from one of the club's longest serving players.

United confirmed the addition of Di Maria for a British record £59.7m from Real Madrid on Tuesday, their fourth signing of a summer which has seen the club miss out on a series of high-profile targets and fail to replace the departed Rio Ferdinand and Nemanja Vidic.

Argentine Marcos Rojo is expected to play in a new United back-three which, while it represents a continuation of Louis van Gaal's tactics from his spell as Netherlands coach, has failed to ensure a win from the club's opening two Premier League matches.

Defeat to third-tier Milton Keynes Dons in the League Cup second round further highlighted the need for defensive resources after van Gaal made 10 changes from the draw with Sunderland, and Lou Macari is in disbelief as to how the manager continues to ignore the club's obvious deficiencies.

"We're all hoping Di Maria will be a great signing," Macari, who made over 400 appearances for United across an 11-year career at Old Trafford, told talkSPORT. "I hope he has enough in him to help turn things around.

"The club have plenty of players in the midfield and up front who can do the damage and that is why I thought more defenders would be coming in as a priority.

I was a little bit surprised when it was Di Maria who they announced.

"I don't think there are many great players going around, so when you have the opportunity to sign one you have to grab them.

"When you lose players like Evra, Vidic and Ferdinand to start with – three out of your back four – victories and wins come on the basis of a sound back-four that is guaranteed to be solid for most of the time, so they have started the season with players who have not played a great deal of football.

"Do you get away with it in the Premier League? No you don't. It was a poor result against Swansea and let's face it a struggle against Sunderland.

"I just hope they [defenders] are coming before the window closes because it is staring everyone in the face that at the back there is a lack of cover to start with. Even if the current defence stays fit, which let's face it they haven't during their United career, then you still need cover and I am amazed they haven't got that cover.

"You look at the games coming up they're all winnable, but then you go into games against Manchester City, Chelsea, Liverpool and Arsenal – all the tough games and I am not being funny if you have a makeshift defence you'll lose those games as well."