The Red Devils were recently crowned as 2012/13 Premier League champions but Ferguson felt the players were basking in that glory rather than getting the job done at Old Trafford.
"I am disappointed. I think we have put the tools away. It looked that way to me," he told MUTV.
"We made some changes of course. We needed to give (Tom) Cleverley, Anderson and Anders (Lindegaard) a game.
"But there was no edge to our game, Chelsea were the better team."
When asked if his United side had switched off, Ferguson added: "I think so. That has a lot to do with it. It has been a long season.
"The final big effort was last week against Arsenal. Today, the edge to the game was off."