Mourinho was speaking after a vital win in the chase for a top-four Premier League finish.
Spurs responded to an embarrassing Europa League exit at the hands of Dinamo Zagreb with a 2-0 win at Aston Villa on Sunday, courtesy of goals from Carlos Vinicius and Harry Kane.
Captain Hugo Lloris had strongly criticised the underlying culture at the club in a stinging interview following Thursday's loss in Croatia, pointing the finger at fringe players who were not fully committed.
Mourinho appeared to agree with that assessment, saying it was difficult to keep a harmonious dressing room in the modern game.
"Football nowadays is not easy in relation to that," he told Sky Sports. "The selfishness is around, the individual interests are around, the agents are around, the connections between agents and press are around.