Bent, who played alongside Bale for two years at White Hart Lane, has expressed doubt over whether the player that impressed for Spurs and for large parts at parent club Real Madrid will ever get back to his best.
"It's a gradual process but at the same time it's a year loan," Bent told talkSPORT. "For me, the question you've got to ask is how long is [Jose] Mourinho prepared to give him before he goes 'this is not working'.
"All the talk has been about Son [Heung-min] and [Harry] Kane being superb, but when they get Bale back, when Bale gets back to himself, Bale this and Bale that. But right now he's nowhere near the Bale we can remember.
"He's not played consistently for about three years and he's had big injuries as well, so that Bale may never come back."