Czech Republic shot-stopper believes that the Red Devils have taken a risk by signing the young Spaniard, insisting that he has huge expectations to match at Old Trafford
Edwin van der Sar called time on his career at the end of last season, having spent six fruitful years at the club, during which time he helped the Red Devils win four Premier League titles, one League Cup, a Champions League and a Club World Cup.
Van der Sar made 265 appearances for United, and the Czech shot-stopper is wary of a player who is half the age of the former Netherlands international and who has made only 84 competitive appearances so far in his career.
"It’s a huge advantage for Manchester United to have a goalkeeper who is 20-years-old because he can stay for many years," Cech told Sky Sports News.
"It’s a huge gamble at the same time because he’s joining, historically, a very successful club with great [former] goalkeepers like Peter Schmeichel, Edwin van der Sar, and we all remember how many years it took to replace Peter Schmeichel.
"So let’s see what is going to happen now Edwin van der Sar has retired because it’s a huge task to fill the boots of Van der Sar."
The 29-year-old also believes that the appointment of Andre Villas-Boas could see the Blues finally enjoy a period of continuity, after having plied his trade under six different managers in his seven years at the west London club.
"Andre Villas-Boas is the youngest we’ve ever had so he can stay for 30 years to be coaching Chelsea football club if the success goes, and everything goes, well. So let’s hope," said the Czech Republic international.
When quizzed if he actually believes that such a thing would come to pass, Cech said: "I think it will be exciting to see if he can be the manager for five years at least."
Earlier, Cech was quoted as saying that the new Chelsea boss could potentially match Sir Alex Ferguson at Manchester United in terms of longevity in his current job.