Mourinho has never made it a secret about his desire to improve the quality of players at the club.
He believes club chairman Levy can help him improve the team so they can compete at the highest level in the Premier League and in Europe.
Spurs have endured fixture congestion since the start of the season due to their involvement in the Europa League.
Mourinho told reporters: "More than the squad, it is time to work and time for evolution.
"It is time to affect the team not just the way we play, but the way we think - sometimes the way we think takes more time than other things.
"I am very happy with the squad but, of course, next summer we will need to give a couple of touches but this is what you always do to improve the squad.
"Look at Liverpool, for example, when Jurgen has been there. How many transfer windows? He went to the market and improved the team."