PSG visit Napoli in a crucial Champions League clash, the two sides having drawn 2-2 at the Parc des Princes last time out. Napoli are a point behind Group C leaders Liverpool - who visit Red Star Belgrade - with PSG a point further back.
Were Cavani to feature it would be his first appearance at the San Paolo since moving to the French capital in 2013.
When asked about Cavani's chances of playing, Tuchel told a pre-match media conference: "I can't say, it's Monday afternoon so I can't say who will play.
"Cavani is with us and he's trained, we'll see later."
Tuchel did, however, confirm that goalkeeper Gianluigi Buffon would start with the veteran available after serving a three-game Champions League suspension for comments about referee Michael Oliver after his decision to award a decisive penalty to Real Madrid in their quarter-final clash with Juventus last season.
Buffon has played a bit-part role in his first season with PSG, splitting time with Alphonse Areola, but was in between the posts for the 2-1 league win over Lille last Friday.
Tuchel is hopeful Buffon's long history in Serie A will be an aid to his team-mates in a hostile environment.
"Gigi and Thiago [Silva] will help us, Gigi already knows the stadium and the atmosphere and he'll be a big help in the dressing room," Tuchel added.
"We have confidence in Areola too, but Gigi is coming back from a ban and he deserves to play in Italy against a team he knows.
"I'm proud to have two goalkeepers who respect each other very much, it's beautiful."