The forward sat out Paris Saint-Germain's 4-0 win over Angers on Saturday with a thigh injury, but the French football federation didn't disclose Mbappe's issue in its statement. He'll undergo treatment with PSG.
Injuries have hampered Mbappe this season. Hamstring and thigh problems have restricted the 20-year-old to only three Ligue 1 starts and a cameo off the bench in the Champions League. He last featured for his country when he scored in the 4-0 defeat of Andorra in June.
Plea, who won his only international cap during a friendly against Uruguay in November 2018, replaces Mbappe after impressively notching four goals and four assists across seven Bundesliga appearances for Monchengladbach this term.
He didn't register on the scoresheet in Europa League outings against Austrian side Wolfsberger AC and Turkey's Istanbul Basaksehir.