The Portuguese also aimed a dig at the spirit of the champions, who have taken only four points from their first four matches this season, and said that three substitutions were not enough as his team went down 2-1 to a fired-up Crystal Palace.
In two spells at Chelsea the 52-year-old holds the highest win percentage record of any of the club’s managers but this is by far his worst start to a campaign.
Saturday’s embarrassment came on the back of a lacklustre opening draw at home to Swansea City, a 3-0 drubbing at Manchester City and an unconvincing win at West Bromwich Albion in which captain John Terry was sent off.
“I’m not happy and for me a performance is a collective performance and obviously to perform collectively you need individual performances,” a grim-faced Mourinho told reporters.
“I cannot say I had 11 players performing together, two or three players were not good,” he added without naming the culprits.
“I blame myself for not changing them and when I made the third change (substitution) I realised I needed a fourth.”
Mourinho brought on midfielder Ruben Loftus-Cheek and fellow 19-year-old, Brazilian forward Kenedy, as Chelsea chased the game in the second half.
Palace, well organised at the back and dangerous on the break, deserved the victory achieved through second-half goals by Bakary Sako and Joel Ward either side of a first Chelsea goal from Radamel Falcao.
Mourinho heaped praise on his south London visitors, highlighting the spirit his side appeared to lack.
“They came with everything,” he said. “The team was ready, the fans were ready, they played with a fantastic spirit, they deserved a lot and they fought a lot,” he said.
But a Mourinho news conference rarely passes without a complaint about injustice and he said Chelsea should have had a penalty when defender Kurt Zouma appeared to be fouled by Connor Wickham.
The Portuguese refused to rule his team out of this season’s title race because the league had become even more competitive.
“In another league I would say game over. In the Premier League I do not say game over,” he said.
“We’ve had a bad start. Four points in four matches is a very bad start.”
(Editing by Tony Jimenez)