From being an outcast last season, Ndombele has established himself in Mourinho’s first team and he could start Thursday night’s Europa League tie against Ludogorets after the manager said Spurs missed the midfielder in the defeat at Royal Antwerp last week.
Mourinho said: “In this moment, I’m happy [with him]. I still think he can do better. His potential is huge.
“Is he doing well? Yes. Am I happy with him? Yes, I’m happy with him but I still think that he can do more.
“He can be fitter, he can give us 90 minutes without problems. He can be better than he is.
“Of course he’s happy because he’s playing, I’m happy because he’s doing important things.
“I see the future probably better because as I was saying his potential is great, but I have to try to educate players, I have to try to give my best.
“I’m not here to be their best friend, I’m here to be their coach above all and I will never be different to what I am. So when I’m not happy, I’m not happy. At this moment I’m very happy with him.”
Ndombele struggled to settle at Spurs in his maiden season following a club-record £55million move from Lyon but he was particularly helped by compatriot Moussa Sissoko, who labelled himself “Tanguy’s big brother”.
“Last season was tough for him and I can say that’s normal,” Sissoko said. “You are a young player, you change country, you are living alone, and don’t speak the language, and the training session is totally different and even the league where you play.
“Sometimes people need time to adapt. It was the case even when I came to Tottenham.
“I was just saying to him to stay calm and be patient and just to work on training and try to understand everyone here.
“[I said:] ‘Maybe this year will not be great for you but everyone knows you have talent and you have shown it in the past and if you came here it is because everyone has seen you perform’.
“You can see that this year he is very happy to be part of the team and he is showing a lot of quality on the pitch.
“All the players are happy to have Tanguy in that form and I think he will even improve during the season but what he is doing and showing is good at the moment.
“He’s not a different person but he’s just more open with everybody [now],” Sissoko added.
“Because last year it was complicated for him here and when things are tough and you don’t speak the language, it’s difficult to open up and speak with everyone.
“This year he’s totally different. Maybe because he’s been playing well, and his English is improving a lot so he can speak with players in the changing room.
“He’s laughing and joking with everyone. That’s good, that’s what we wanted to see.”
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