Sigi told The Sun: "If you look at his record at Porto, it was unbelievable. He won the Double and Europa League.
"Obviously it didn't work out at Chelsea but he's still a fantastic manager.
"All of the boys in the first week in training have been very happy with him and his sessions and his ambitions. Training has been very lively and he gets involved a lot.
"There have been many great managers who have gone to Chelsea and it hasn't worked out for them.
"It's probably one of the hardest jobs in the world to go to Chelsea. When things don't go right, you are in trouble but he's more than determined to do well with Tottenham. You can see that in training.
"He's young, he's got a great future ahead of him. he's a fantastic manager and that's why Tottenham brought him in. Everything's here for him to do well."