The Frenchman has come in for criticism after the Gunners' poor start to the season, but Redknapp is convinced that it is only temporary.
"You know what it's like in football. You lose a few games and suddenly Arsene Wenger's a poor manager," he told reporters.
"The man's been a great manager at Arsenal and I am sure he will be for many years to come. God knows what people are saying about him on the radio."
The Spurs boss also believes that his side has a good chance of beating their North London rivals at White Hart Lane this weekend.
"They'll be difficult to beat but we are a very good team as well so I fancy our chances against anybody," he added.
"I am confident in my own team. I just feel we have good players here."
Tottenham go into the match in sixth place in the table, while Arsenal currently sit in 13th.