The Transfer Zone uses the Football Manager database to look more in depth at transfer stories and situations The Transfer Zone uses the Football Manager database to look more in depth at transfer stories and situations

Manchester United "must find replacements" for the forwards that have left the club this summer, Tony Cascarino has told Sky Sports News HQ.

Angel Di Maria will join Robin van Persie and Radamel Falcao in leaving Old Trafford if he completes a widely expected move to Paris Saint-Germain.

And former Aston Villa and Chelsea striker Cascarino believes these departures are cause for concern.

"Their midfield has been bolstered (by the signings of Bastian Schweinsteiger and Morgan Schneiderlin)," Cascarino said on the Transfer Centre.

"But if you think they will have lost Di Maria, Falcao and Van Persie, that’s a huge loss to Man United.

"They must find replacements. If they lose Wayne Rooney (to injury), they’ve got a problem."

Van Persie’s transfer to Fenerbahce and Monaco loanee Falcao’s switch to Chelsea leaves United with just two established recognised strikers in Rooney and Javier Hernandez, who has also been linked with a move away.

But Cascarino believes that United are not the only big club with problems to address before the transfer window closes, suggesting that Arsenal should "add another centre-half" in their bid to fight for the Premier League.

"Another defender at the heart of their backline would be a massive statement for Arsenal," said Cascarino. "But they’re a much better side than the one we’ve seen in the last couple of years. They look ready to challenge now."

Cascarino also highlighted defensive deficiencies at Manchester City, but believes the answer to this lies from within.

Tony Cascarino says Man City need to focus on getting Vincent Kompany back to his best

He said: "Defensively, they’ve got to get more out of Vincent Kompany. He’s still a young man. If City can get him close to what he was before, that’ll be (like) a massive signing."

Cascarino has, however, been impressed by the business done by Liverpool manager Brendan Rodgers in this transfer window: "I think he (Rodgers) has got a lot better than last year. (Christian) Benteke fits in perfectly with what they’ve got.

"Brendan has really hit it (the transfer window) hard and I really like a lot of his signings."

But Cascarino says he has been most impressed by some of the signings made by clubs not looking to challenge for the title.

Crystal Palace new boy Yohan Cabaye is a 'top six player' according to Cascarino

"Look at clubs like Crystal Palace," the former Republic of Ireland international said. "(The signing of Yohan) Cabaye is a big statement. He could be a top-six player in any league in Europe, and I’m sure (Chelsea loanee) Patrick Bamford will score goals."

Cascarino, who spent six years playing in France with Marseille and Nancy, praised defender Micah Richards for returning to the Premier League with Aston Villa after a stint in Italy.

"I’m delighted to see Micah Richards (at Villa). He went to Fiorentina, and fair play to him," he said.

"He should be proud because not many players are prepared to go and do what he did. He went and played abroad, came back and he’s got his rewards."