Wayne Rooney has called on Manchester United to bring in two new signings before the transfer window shuts, insisting it would be “crazy” for Ruben Amorim not to go after Gianluigi Donnarumma.

Manchester United have invested close to £200m this summer, strengthening Ruben Amorim’s squad with the arrivals of Benjamin Sesko, Matheus Cunha and Bryan Mbeumo.

Despite suffering a 1-0 defeat, Manchester United showed signs of progress in their opening-day clash with Arsenal, where the hosts capitalised on an error from stand-in goalkeeper Altay Bayindir.

Andre Onana had been Amorim’s first-choice keeper last season, and the United manager clarified that his omission against Arsenal was a tactical call, not due to injury.

Although Amorim seemed to have doubts about Onana and saw Bayindir make a costly mistake, he maintained that he was satisfied with his current goalkeeping options and hinted that Manchester United were unlikely to pursue a new keeper in the transfer market.

But club legend Rooney believes the goalkeeping situation at Old Trafford is an ‘issue’ and says it would be ‘crazy’ for Manchester United not to pursue a deal for Donnarumma.

The Champions League and European Championship winner is currently looking for a new team after being frozen out by PSG manager Luis Enrique, despite delivering outstanding performances last season.

Donnarumma is willing to make a switch to the Premier League, but Manchester United have made it clear they are not pursuing his signing.

‘There’s the goalkeeper situation and I’m sure every Man United fan is asking the same question,’ Wayne Rooney said on his BBC podcast.

‘For me, Donnarumma is out there and if there’s a possibility you can get him, you have to go for him. Clearly that [the goalkeeper] is an issue.

‘I go back to when we had Roy Carroll and Tim Howard in goal. I don’t think there was 100 per cent trust from the defenders in front of those two goalkeepers.

‘But the minute [Edwin] Van der Sar came in and calmed everything down, the defenders trusted him a lot more and you see a better output of performance.

‘These United players want that confidence and trust in the goal behind them and I just don’t see that with the ones we’ve got at the moment.

‘With Donnarumma, he’s 26 and one of the best keepers in the world. It would be crazy if Manchester United didn’t go for him.

‘If the deal can be done and what Donnarumma wants [in terms of a salary] is another question but I’d certainly be asking the question and try to get him to the club.

‘Andre Onana is a fantastic keeper, I watched him at Inter [Milan] and he was brilliant.

‘So you hope if they don’t sign a new goalkeeper he can get back to that level of form, but he certainly didn’t fill us with confidence last season.’

Although Manchester United are not looking to recruit a new goalkeeper at the moment, they are exploring midfield reinforcements.

Brighton’s Carlos Baleba has emerged as a leading target, while Crystal Palace’s Adam Wharton is also on their radar — but both players are expected to command hefty fees.

When asked if he would be “crying out” for a new midfielder in Amorim’s position, Rooney replied: “You would be, yeah, but obviously we don’t know what the situation is with PSR.”

‘But to get a midfielder and a goalkeeper is a priority, if they can address that before the window closes they will be in an okay place.’

Rooney stressed that he saw “many positives” in Manchester United’s loss to Arsenal, believing it showed the team are “on the right track” under Amorim.

However, Amorim’s position could come under serious pressure if United fail to deliver major improvement this season, having finished as low as 15th in the Premier League last term.

‘I think there were so many positives for Manchester United throughout the game,’ former captain Rooney added. ‘The players will be disappointed to lose but for the fans there were positives to take.

‘It’s not going to completely change in one transfer window, it’s going to take a bit more time, but it looks like they’re on the right track now.’

Amorim’s men resume their Premier League campaign on Sunday with a visit to Craven Cottage to take on Fulham.

Fulham kicked off their season with a 1-1 draw against Brighton, courtesy of Rodrigo Muniz’s stoppage-time equaliser.