PSG suffered a rare setback in midweek as they dramatically lost 2-1 to Guingamp after conceding three second-half penalties.
Neymar and Mbappe both played the full 90 minutes, with the latter taking a blow to the head late in the first half, and Tuchel revealed on Friday that the pair are tired and may be rested as Ligue 1 action returns for 2019.
"For Mbappe and Neymar, we must see after training if they will play," he told a news conference. "It is uncertain."
Gianluigi Buffon and Prisnel Kimpembe are among those also out, yet the PSG coach sees an opportunity for the league leaders to move on swiftly from the Guingamp defeat.
"Everyone in the squad was a little sad after the defeat to Guingamp," Tuchel continued. "No matter how much you win, you still feel this pain.
"But now it is necessary to show a reaction so we can forget about this match. For this, it is good to have another game straight away.
"The defeat against Guingamp cannot influence my team selection, though. [It looked like] we did not want to play that game, but I understand the players.
"We cannot play 60 matches with the same emotional state, the same concentration. It is not easy to always be 100 per cent motivated throughout the season. We ran out of energy."