Alvaro Morata or Romelu Lukaku can fill attacking void at Manchester United says Andy Cole

Manchester United should sign either Real Madrid's Alvaro Morata or Everton forward Romelu Lukaku to fill an attack which is expected to be without Zlatan Ibrahimovic next season, according to former striker Andy Cole. The former Sweden international is not expected to be retained for the 2017-18 campaign having suffered a serious knee injury which will keep him out of the start of next term.

And with captain Wayne Rooney also likely to depart amid interest from the Chinese Super League and former club Everton, Jose Mourinho has made signing a new forward his priority in the summer transfer window. The Europa League and English Football League Cup winners have however withdrawn from attempts to sign Antoine Griezmann after the Frenchman declared his intent to remain at Atletico Madrid.

Real's out-of-favour forward Morata has emerged as United's chief target in recent days but the La Liga and Champions League winners are demanding a fee of £78m to lure him from the Bernabeu, according to The Daily Telegraph. Lukaku, who was only outscored by Harry Kane in the Premier League last season, has also been linked with a move to Old Trafford but the Toffees are demanding £100m, claim the Liverpool Echo.

"It is very difficult because when you are talking about strikers now there are not many out-and-out strikers," said Cole, who scored 93 goals in 195 United appearances, said according to Sky Sports. "When you are talking out-and-out strikers you think of Robert Lewandowski at Bayern Munich but you cannot see them selling him.

"Alvaro Morata at Real Madrid can't get in the team but he was fantastic the year before at Juventus. You then start to think 'Who else is there?'. There aren't many out there. There is talk of (Romelu) Lukaku. It is very difficult to see who is out there United could buy. Look around world football and there aren't many to bring to a club like Manchester United.

"Everybody is looking for the same thing and all Premier League clubs can afford big money now. It is going to take a lot of money and a lot of persuading but it is easier now we are back in the Champions League."

But after calling off attempts to sign Griezmann, United's seperate pursuits of Morata and Lukaku may yet be thwarted also. The agent of the Real forward says his client wants to remain in Madrid capital in order to cement his place in the Spain squad for the 2018 World Cup in Russia. Meanwhile, Lukaku says talks are underway over his next move, but has refused to confirm where his future lies.