The RB Leipzig forward has been on loan at Spurs since the January transfer window.
Asked about Werner this week, Son said: I think he listened to what the gaffer asked for.
The way we approach the game, the wingers are very important, staying wide and being in the right position. And Timo and Brennan are doing a great job, both understanding each other.
When he came to Tottenham, (Timo) was missing a little bit of confidence, but now you can see he's playing with confidence and more comfortable missing a few chances, but that will come.
He's doing a great job, but as I always said, he's a Golden Boot winner in the Bundesliga and we expect he'll score and give assists more for the team, because we have massive games ahead.
I always want to make good friends and good team-mates, but in football there are no guarantees and the club will make a decision. But Timo would happily stay here, I can see that.
As a player, I want to help him so he has a better option than right now. That's a team-mate's job. We'll see what's going to happen at the end of the season. I can say I want him to stay."