David de Gea had it tough when he first joined Manchester United. Really tough.The Spanish goalkeeper was just 20 when he completed his £18.9 million move from Atletico Madrid to Old Trafford in June 2011 - and he was far from the finished article.At the time, De Gea was physically slight and Premier League clubs soon discovered that putting him under pressure would lead to goalscoring opportunities.The more mistakes he made, the more of a target he became. It was a vicious circle and one that many football fans were convinced would continue indefinitely.There were even United supporters who doubted whether De Gea would ever be cut out for the hustle and bustle of English football.

Ferguson eventually dropped De Gea for Lindegaard

And Sir Alex Ferguson eventually took De Gea out of the firing line, dropping the youngster for Anders Lindegaard following errors against Basel and Blackburn in the December of his first year at Old Trafford.

United crashed out of the Champions League group stages during the 2011-12 campaign following a 2-1 defeat at the hands of Basel and De Gea faced a barrage of criticism for his disappointing performance.

What Szczesny tweeted about De Gea in 2011

However, one man who stuck up for United’s under-fire No. 1 following the Basel match was Arsenal’s young ‘keeper Wojciech Szczesny.

Taking to Twitter, the Poland international explained why De Gea would prove his doubters wrong in time.

“I don't agree with De Gea criticism,” Szczesny tweeted. “He's potentially one of the best GK in the world but needs time to get his confidence at ManUtd!”

He added: “You have to perform at your best every game when you play for big clubs and when De Gea is at his best he is UNREAL! Give him some time…”

The turning point in De Gea's United career

An injury to Lindegaard saw De Gea return to United’s starting line-up and the turning point of his career came in a 3-3 draw against Chelsea at Stamford Bridge on 5 February 2012.

The youngster pulled off a stunning save from Juan Mata and that increased his confidence tenfold.

“[There were] some moments where you think ‘that’s not my place, I have to come back to Spain’. The weather, the language. There were difficult moments, but I fight,” De Gea told Avtex Sports, per Goal, in 2016.

“Juan Mata, the free-kick, probably was the point [where] everything changed. I played better, better, better.”

Five years later and De Gea is widely regarded as one of the best goalkeepers in the world, if not *the* best goalkeeper in the world.

Szczesny saw the future.