His appearance off the bench could pave the way for a start against Rennes at Stade de France on Saturday, with Tuchel dismissing responsibility for Neymar's pre-match movements.
"I do not know about it," Tuchel told reporters on Friday.
"I'm not his father, not the police, not a detective.
"I'm the head coach and he was at training yesterday and with us today. That's it."
Neymar's involvement in the 3-1 win over Monaco coincided with Edinson Cavani's return from a hip problem as Tuchel welcomed back the remaining two thirds of his star-studded front three.
Kylian Mbappe, a pivotal figure in their absences, stole the limelight with a hat-trick that improved his Ligue 1 tally to 30 goals for the season, becoming the youngest player to reach the mark.
"He's been a reliable player, a decisive player," Tuchel said of the 20-year-old France international.
"His status is growing, he's getting more important, but I think he enjoys it and he's ready for it.
"We are not talking theoretically here. Everything happened naturally. He took on more responsibilities.
"I have several key players in my team and it's always a team effort as we demonstrated during important games this season.
"We have to showcase once again tomorrow for 90 or 120 minutes that we can play together, defend together, but Kylian has done really well and he's extraordinary, that's for sure."