Assou-Ekotto was behind Bale, Lee Young-Pyo and Gilberto in the pecking order a year ago but has been a regular under Redknapp since the manager's arrival at White Hart Lane last October.
Redknapp has been linked with Porto full-back Aly Cissokho but has also been impressed with the improvement from Assou-Ekotto.
"He has done very well," Redknapp said. "I think he has been injured before but I have been very impressed with him this season as he has been in great form. He has looked an outstanding left-back."