Chelsea have slumped to consecutive defeats this week at home and in Europe.
Grant told talkSPORT: "It's only the beginning of the season though. Jose is still a good manager and the squad is the best in the Premier League.
"The biggest problem at the moment is that they're not playing well, but the good thing is that it's only the start of the season. They have the quality to play better.
"The squad have to be positive, it's a fantastic squad. They have bought some good players, but they just need to play better."