Tottenham Hotspur manager Jose Mourinho played down expectations on forward Gareth Bale, saying the Welshman cannot be the same explosive player who left the Premier League 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, including Thursday's 1-0 Europa League defeat by Belgian league leaders Royal Antwerp.

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.

"Seven years is a long gap, so which player in the world is the same as he was seven years ago? Sometimes they're not better or worse, just different players," Mourinho told reporters.

"You look for example to (Cristiano) Ronaldo and (Lionel) Messi and compare them with seven years ago. They play in different areas, different positions.

"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.

"He didn't miss a single minute of any training session. To play 90 minutes is still hard, to play high intensity is still difficult, but he's improving and hopefully he'll be back to a better level soon."