Reyes is enjoying his best form in an Atletico shirt under Flores and Rivas, who works with several Primera Liga clubs, told AS: "He is a player for which trust is fundamental to his game.
"If Quique remains confident with him, his performance will grow exponentially. And we'll see the best of Reyes. It's what we're seeing now.
"Technically and physically he was fine, but, having no confidence in himself and not being motivated by the coaching staff, he gave up.
"If he continues along this new path, the best is yet to come."