The Reds have impressed in the early stages of the season and sit third, level on points with the Portuguese's Blues.
Asked by Chelsea's official magazine about their fellow title contenders, Mourinho observed: "Liverpool are probably the club with least resources because, while their team looks as strong as the others, their squad doesn't look quite so strong.
"At the same time, they don't play in European competition, so they only play one match a week, so they are training, preparing and resting for the weekend match while the rest of us are playing in Europe.
|21/1||Chelsea are 21/1 with BetVictor to beat Schalke 4-1 in the Champions League|
"Tottenham is the big spender of the summer and, because of that, they have a fantastic squad with two teams of equal players.
"At Arsenal, the manager is building a team step by step – the club is stable and buying a player like Mesut Ozil makes a difference."
Despite his reputation as a difference-maker in the dugout, meanwhile, Mourinho rejects the notion that some managers are tougher to face than others.
"I think it depends more on the players and the teams than the 'tricky' managers," the ex-Real Madrid coach argued. "The tricky manager is only tricky because he has the players at his disposal to be tricky.
"I keep thinking that we managers don't make miracles, we just work with the qualities our players have, so I prefer to talk about difficult teams than difficult managers."