The Premier League leaders stretched their advantage at the top to seven points thanks to an uncompromising 0-0 draw at the Stadium of light, a 20th game unbeaten to start the season.
Mourinho sent out an unchanged line-up less than four days after the 5-0 romp at German side Schalke guaranteed their place in the knockout stages of European football’s top club competition.
But the Chelsea manager saw his side fade visibly in the final quarter of their first of eight games in a hectic 34-day period leading into 2015 that will play a big part in shaping the destiny of their season.
He admitted Sunderland’s greater preparation time had played a significant role in the London club failing to add to their nine-match winning streak on Wearside.
“Sunderland’s players will have watched our game on Tuesday at their homes, and they will have gone to bed at 11pm,” said Mourinho.
“We arrived at home from our game at 5am on Wednesday, and that’s something I don’t forget, so for this reason I praise my guys. They deserve their Christmas party, that’s for sure.
“Sunderland had a full clear week to prepare for this match, and to develop a strategy against us. Some people might like to criticise defensive teams, but I don’t, because they did it very well against us and achieved their goal of a clean sheet.
“We’re not happy with a point, but we have to be mature enough to realise that in this league, every match is difficult.
“I have no negative words for my players, because they tried everything they could to win the game, and in the end it was a fair result.
“There’s no time to be complaining, because we move on to another match on Wednesday where we’ll try to get the points.”
Mourinho is forced into at least one change, as the Blues’ 12-goal top scorer Diego Costa will miss the visit by Spurs through suspension after earning a fifth booking for catching defender Wes Brown with a flailing arm in the second-half.
The Chelsea manager refuted suggestions the Spaniard was fortunate to avoid a red card after escaping censure for a studs-up first-half lunge at Sunderland skipper John O’Shea.
Mourinho added: “I’ll play Loic Remy or Didier Drogba instead, they have an opportunity to play on Wednesday as Costa is suspended. We don’t cry about injuries and suspensions, and missing out will mean Costa is fresh to face Newcastle next weekend.”
Sunderland climbed three points clear of the relegation zone, thanks to an eighth draw of the season, their fourth in a row unbeaten.
They host Manchester City on Wednesday, and the former Chelsea midfielder said: “We have to be pleased with a point. In terms of our display it was the best for a while. You can talk as long as you like, but it’s what happens out on the pitch that matters.
“We put in a great defensive display and Chelsea didn’t have an easy chance all game, which is testament to the way we played and how well we defended.”