After recovering from coronavirus, Brazilian forward Neymar is back in training with PSG and appears likely to be involved in Sunday's big match at the Parc des Princes.
He missed the 1-0 defeat to Lens as the Champions League runners-up made a disappointing start to their domestic campaign.
Neymar was one of a host of star names to be ruled out of that match after COVID-19 positive tests, but he, along with goalkeeper Keylor Navas, playmaker Angel Di Maria and midfielder Leandro Paredes have now returned negative results.
They, along with new signing Alessandro Florenzi, are in line to play some part, with Tuchel waiting until a light training session on Sunday before settling on his line-up plans.
"We won't be taking risks," Tuchel said. "That is not what we are going to do. After two days of training, if the players are ready and there are no medical risks we will make the decisions.
"I don't need to ask them if they want to play, but I'll have to decide [on Sunday]. It will be a question of whether they start on the pitch or on the bench."
The German head coach cannot understand why French league chiefs decided such a headline fixture should come so soon this season.
"I am surprised that such an important game is scheduled for the third match day," Tuchel said in a news conference.
"I think such a game should be scheduled for October or November when both teams have got into a rhythm.
"Everybody wants to win at their best level but it's not possible if it's only the second game in Ligue 1. Personally I don't understand the decision."
Yet PSG are determined to take a positive attitude into their home fixture, seeing the opportunity to relaunch their campaign after the false start.
"We're not afraid. We're ready to play every match," Tuchel said. "We know our fans love it when we win matches like this. It's not easy for us. We have to adapt and prepare to overcome the obstacles in matches like this."
Tuchel confirmed Marquinhos, Mauro Icardi and Kylian Mbappe, who also tested positive for COVID-19, will miss the Marseille match.
But the overall picture is looking increasingly positive, as PSG target their first points of the campaign.
"We want to show we want to win again, that we wanted to keep winning after a loss," Tuchel said.
"I can understand that some teams think it is the only time and the only moment to really face us and beat us, so maybe, yes, it is a good time to play against us, but we still have our features and qualities and we will show them that tomorrow."