The former Blues midfielder will lead the Black Cats into battle with Mourinho's men at the Stadium of Light on Wednesday evening desperately looking for a fourth successive home victory in all competitions to help ease their relegation fears.
However, while that might prove a blow to the second-placed London club's hopes of reeling in leaders Arsenal - the Gunners are currently four points better off - the 46-year-old is confident they will be involved in the mix come the end of the season.
Asked if Chelsea, who came from behind to beat Southampton 3-1 on Sunday, could go all the way as a result of Mourinho's return to Stamford Bridge, Poyet replied: "Yes, no doubt about it.
"They are different, they are stronger. The reaction at the weekend at half-time was all about the mentality of the team more than even the play or the technique or the ability.
"It was mental. It was a completely different team in the second half. I am sure there was a unique half-time team-talk in the dressing room or wherever it happened. It was a complete turn-around.
"I know him [Mourinho] and I admire him a lot. He's a different-class person and manager. I know him in football ways and as a person and I am looking forward to seeing him before the game.
"Then the game is the game and I hope everything goes all right and there are not any problems in the game between the benches.
"I had the opportunity to watch him training a few times at Chelsea and it was very impressive."