Morata moved to Madrid in January on-loan.
He told Goal: "As I arrive at the training centre (at Atletico), you can see in people's faces when they trust you. When you are in the dressing room ahead a game, you see how your team-mates look at you.
"At Chelsea there came a time when my team-mates, except for the Spaniards, well... you know, it is not the same when you play and you know that you give a pass to someone who is not going to do as well.
"You do not give the pass in the same way. Everyone who has played football once will understand that."