Mbappe was officially presented to Madrid supporters at the club's Bernabeu Stadium on July 16 following his summer switch from Paris Saint-Germain.
But the former PSG frontman has not since featured in any of Madrid's pre-season friendlies.
He was not named in the matchday squad for Saturday night's 2-1 Clasico defeat by Barcelona in New Jersey and he may also miss Tuesday's exhibition against Chelsea in North Carolina.
Madrid's next game after that will be the UEFA Super Cup final against Atalanta at the Kazimierz Gorski National Stadium in Warsaw on August 14.
Ancelotti has said that he expects Mbappe to feature - possibly as a starter - in that contest between the winners of last season's Champions League and the reigning Europa League winners.
The Italian also confirmed that Jude Bellingham is set to play in that match.
'Mbappe can obviously play in the Super Cup from the start,' Ancelotti told Mundo Deportivo. 'Jude Bellingham too and others. They are prepared, they have followed a plan and will all play.'
Bellingham was given extra time off by Madrid after being part of the England team that went all the way to the final of Euro 2024 this summer.
Meanwhile, Mbappe captained the France side that were beaten by Spain in the semi-finals.
Carlo Ancelotti (pictured) has said that Mbappe and Jude Bellingham will both play for Madrid in the UEFA Super Cup final against Atalanta on August 14
Mbappe won 15 trophies during his seven seasons as a PSG player but he was unable to win a continental title with the French giants.
However, Mbappe could well win the first European title of his club career in his very first game for Madrid.