Roy Hodgson's Palace are 11 points above the relegation zone and 11 points shy of sixth-place with 11 matches remaining in the campaign.
"I always feel these type of teams with real quality but without any real pressure to do better than have a stable season, they just go and play," Mourinho said.
"If they win, great. If they lose, they don't feel any pressure from media or fans. It is a nice way to play and compete.
“They will come here to try and not concede goals, which they do well. But they will try and score and they have danger from different items of the game, so I expect a difficult game.
"They defend well, they have a lot of good defenders, people who enjoy defending, enjoy playing in a defensive team.
“A very good coach. Roy and his staff, they know very well how to play the 4-4-2, they are aggressive in the counter, they are good at set-pieces, they have giants who can win the ball and can win he game in the opposition half."