Morata, 24, left Real for the Premier League champions in the off-season, for a club-record £60m (R965m) fee, citing a lack of trust from the French tactician.
Despite winning the UEFA Champions League, the LaLiga title and scoring 20 goals in 43 games, the Spain international felt he was part of 'B' team under Zidane's leadership.
But the 45-year-old who's lead Los Blancos to seven trophies in his first three seasons's as a top-flight coach strongly denied Morata's claims.
"For me, there are no small games," Zidane told reporters, as quoted via Marca. "Each one is different, and of course everyone wants to play against PSG before other league teams, but we can't think about that.
"His role was fundamental to the team, Morata participated a lot and very well in what we won last year."