Buffon, who joined the Ligue 1 giants in the summer from Juventus, last played for PSG in a 5-0 league win over Lyon on October 7 as he alternates with French shot-stopper Alphonse Areola.
The 40-year-old World Cup winner was suspended for PSG’s opening three Champions League group games.
But he is set to replace Areola in Friday’s league fixture with Lille and again in Naples on Tuesday when PSG will be battling for a win to salvage their flagging Champions League campaign.
“He plays a very important role for us because he’s a legend,” Tuchel said.
“He’s had a great career and has a lot of experience. He’s crucial for us thanks to his approach to the game. LIVE matches Bet Now NaijaBet
“It’s very important that he’s here and that he speaks to everyone to share his experience.”
PSG have won their opening 11 matches in Ligue 1 and sit top with an eight-point lead on second-placed Lille, whom they host on Friday.
But the Parisians realistically need a win in Naples on Tuesday if they are to save a flagging European campaign beset by defeat at Liverpool and a 2-2 draw with Napoli in the French capital.