He said on Saturday that the Welshman cannot be the same explosive player who left the English Premier League (EPL) club to join Real Madrid seven years ago.
The 31-year-old Bale, back at Tottenham on loan from the Spanish side, is building up his fitness and has played three games in all competitions this season.
Mourinho said before that match that Bale was ready to “fly”, but the Portuguese was more measured in his assessment heading into Sunday’s league game against Brighton & Hove Albion.
“They transform their qualities, try to explore their qualities in other responsibilities on the tactical system of their teams.
“I think it happens with the majority of the players. So for sure he’s a different player.”
Mourinho backed Bale to regain his best form with more minutes under his belt.
“Every word I said on Wednesday I believe, because he’s working hard, he’s improving, he doesn’t have one single injury since he recovered from the last one,” Mourinho added.
”But he’s improving and, hopefully, he’ll be back to a better level soon.”(Reuters/NAN)