Arsenal's signing of Petr Cech is widely being hailed as an excellent piece of transfer business, but not everybody is convinced.
Redknapp believes Cech may be a shadow of the player he was, with a key weakness in his game.
He said: "I have a suspicion that, at 33, he might not be the goalkeeper he once was. Jose Mourinho is no mug. Everyone is saying ‘Jose has been kind to Cech’ and ‘he has given Arsenal a big hand’ but let’s see.
"The word is that he doesn’t come off his line as much as he used to and the better teams will exploit that.
"But the last time Arsenal had a keeper of this quality was Jens Lehmann... and they won the title with him."
33-years-old is however a relatively young age for a goalkeeper, with the likes of Edwin van der Sar and Brad Friedel recently playing Premier League football into their 40s.
The big question is whether the year Cech spent sitting on the sidelines at Chelsea last year has fuelled his motivation and given him a needed rest, or whether he has lost a step of sharpness; and Redknapp asking that question on the eve of the season is fair.
|Team||Good High Claims per game||Goals Conceded per game||Errors Leading To Goals||Appearances|
|David de Gea||Man Utd||0.82||1.07||1||74|
Statistics from the last two seasons illustrate Cech concedes fewer goals per game than peers Hugo Lloris and David de Gea.
The figures also bely Redknapp's worry he does not come off his line enough, doing so on average more times per game than De Gea. Whether he can keep to his high standard, is the crucial question.