Now coaching at Heerenveen, Hoek also worked at Manchester United and Barcelona. Hoek coached De Gea, now with Fiorentina, at United.
He told American RG: “I worked with Edwin van der Sar at Ajax, Victor Valdés and Pepe Reina at Barcelona, they are all exceptional, but if you ask me to choose I would go for David De Gea.
“I was very impressed that he was able to play at such an incredibly high level two years in a row. During my time at Manchester United (between 2014 and 2016). He didn't really have a dip, you didn't see him fall.
“He didn't make many mistakes, but he also took many important actions that ultimately earned us victory. He was at an incredible level, three games a week.
“I was also further in my coaching process than with Edwin (van der Sar). We integrated goalkeepers more into the training and I noticed that David (de Gea) became less in his form during the training.
“When I saw that, we sat down together and discussed it, I didn't wait for the games. We were able to solve the problems before it happened during a match, I was able to signal earlier whether something was not going well and tackle it."