The coach reveals that the Uruguayan will be available for selection as the French champions aim to complete a Classique double over their great rivals
The forward has not featured for the Ligue 1 leaders since pulling up with a thigh injury in the 2-0 win over Bordeaux on 31 January but has now proven his fitness.
Speaking ahead of the match on Sunday, Blanc admitted that fringe players Christophe Jallet, Zoumana Camara and Hervin Ongenda will miss out, but confirmed that the club's €64 million acquisition will play some part in the fixture.
"[Cavani] has worked really well this week," the 48-year-old coach was quoted as saying by Fifa.com.
"As long as there are no problems in the last training session [before the game] he will be in the squad. Will he start? You will see."
Marseille go into le Classique 18 points behind les Parisiens but, despite the gap, Blanc insists that the tie still carries a great appeal.
"This is a special match. It always will be in my opinion and we know the reasons for that," the former l'OM defender added.
"But for there to be a bit of spice to it, both clubs need to be doing well. If there is less pressure, it's maybe because you [the press] are creating less.
"There is always this rivalry between the two clubs, between the south and the north, the capital and the province.
"They are solid. The reverse fixture [a 2-1 win for PSG despite Thiago Motta being sent off after half an hour] was one of our best matches, with 10 against 11 for almost an hour.
"We will play our own game. Will they take risks or will they sit back? I don't know. But everyone knows how we will play."PSG are top of the table with 61 points from 26 games with Marseille, currently enjoying a five-game unbeaten run, are fifth with 43.