Newcastle boss Alan Pardew believes it will be "impossible" for Chelsea to remain unbeaten in all four major competitions this season.
Jose Mourinho's men maintained their unbeaten start to the current campaign by brushing aside Tottenham at Stamford Bridge on Wednesday night.
Ahead of Chelsea's visit to St James's Park on Saturday, Pardew hailed the quality of Mourinho's men but said they were bound to slip up sooner or later.
Pardew said: "I think it's difficult - obviously Arsenal have done it and Chelsea have come pretty close before.
"But not in all competitions - that is impossible and I think Jose has admitted that. But they're making a very good job of it at the moment.
"It's the best Chelsea team that I've ever seen and I've watched them since I was about 12 so I know them pretty well. I think Jose is pretty pleased with what he's got."
Pardew is hopeful captain Fabricio Coloccini will be able to make a return on Saturday after missing the best part of a month with a calf problem.
Coloccini has been training with his team-mates this week but Pardew must decide whether he is ready for what is likely to prove one of the toughest possible tests.
Pardew added: "Coloccini has been on the training ground but whether he's got enough fitness levels to play a game of this level I don't know.
"I can't really give a clear message. I'm not trying to hide behind anything but we have had recovery time and I can't really give a clear indication of how the players are."