His final test came on Wednesday night in a 90-minute storm generated by West Ham’s unrelenting brick outhouse Andy Carroll, which at times left Old Trafford boss Sir Alex Ferguson at the end of his tether.

But despite one outlandish challenge by Liverpool’s on-loan striker, which Ferguson felt deserved a red card and which laid the Spaniard out, De Gea stood firm against the aerial barrage.

He even dished out some of his own treatment, with a neat blow to the big Geordie’s head following another coming together in the second half.

To the delight of the Manchester United bench, it spelled out in no uncertain terms that the one-time shy £17million capture from Atletico Madrid had placed a marker – that he wouldn’t be bullied out of the Premier League.

When he arrived to replace Edwin van der Sar at the start of last season, nobody questioned De Gea’s reflexes and shot-stopping skills.

But some early lapses under physical pressure from crosses and corners left question marks and led to a time out of the team.

Now, confirmed his manager, the 22-year-old is with United for the long haul. Ferguson said: “If you remember his first game, at West Brom last season, he got battered.

“I think referees viewed him as a young Spanish goalkeeper who wasn’t tough enough, so he didn’t get any protection at all.

“But now you can see the maturity in him and the physical side doesn’t bother him. He has handled it.

“He took a real buffeting on Wednesday but it didn’t affect him at all. He was composed in everything he did. He has developed into a really top goalkeeper. He is quick and composed. His use of the ball is good. We have no problems with him now.”

United sensed their frail-looking newcomer would be severely tested from day one by uncompromising forwards who could smell blood.

Ferguson added: “When we first agreed to sign him and he came to my house, I got Eric Steele the goalkeeping coach there as well to explain what the game is like in England.

“So he was expecting something different to what he had been used to. It still came as a surprise because having to deal with it all as a young keeper is a different issue.

“In the early days, it was a concern whether he was going to be mature enough to be able to handle that kind of play. Now we don’t have any concerns.

“You can’t really prepare a young goalkeeper for the physical side. Eric does a lot of crossing in training with him and with the other two keepers but you can’t prepare for the real thing. Also, you don’t want players crashing into one another in training.”

He gives credit to his experienced goalkeeping coach for sticking with the young keeper when the going got really tough, while De Gea took to the gym to increase his body strength.

The United boss revealed: “When he was out of the team he worked with Eric every day. I had a couple of chats with him but Eric kept reminding him that he would be the top keeper.

“The improvement is physical. I think he has put on something like a stone in weight now, which is muscle. He is much stronger to deal with the physical part. David is the confirmed No1 now.”