Sessegnon joined Spurs in the summer for £25 million from Fulham on the transfer deadline day, but has only played 33 minutes of football so far this season.
The 19-year-old is in line to make his first start for the north London club against Bayern Munich, reports The Mirror.
Mourinho tried to sign him three times when he was at Manchester Unitedand he compared Sessegnon to former Chelsea and England legend Ashley Cole after finally getting to work with him.
The 19-year-old has revealed what Mourinho told him recently.
“He just sat me down, told me to be myself, told me to be a bit more vocal because I am quite a quiet player and person in general,” Sessegnon said.
“He wants me to show a bit more personality, show a bit more of me, show that I want to play, show that I will fight for my place in the team and a lot of strong words really,
“I definitely need to be more vociferous, 100 per cent.”