Lopez, 20, has enjoyed an incredible breakout season with the UEFA Europa League runners-up, featuring in 44 games across all competitions for Rudi Garcia's side.
He featured just over an hour for the Ligue 1 side against Atletico Madrid on Wednesday, replacing injured captain Dimitri Payet.
Zidane has been aware of the diminutive midfielder's talents due to his friendship with the sons of Los Blancos head coach.
And prior to their 3-0 final defeat to Atleti, he commented on the progress of the reported Real target.
"He played with my kids and he has exceptional technique for his age and size. When we first saw him, we maybe thought he was a bit small, but I'm not surprised by how he is playing now," he told reporters, as quoted by AS.
"It's fascinating what he's doing and his personality really impresses me. He works really hard, sacrifices himself for the team and allows his teammates to play."