Paris Saint-Germain cannot count on just Kylian Mbappe to get over their below-par form, according to head coach Christophe Galtier.
PSG have lost three of their last four matches in all competitions, with a one-goal deficit to overcome in their Champions League round-of-16 tie with Bayern Munich and their hopes of winning a 15th Coupe de France this season over.
A dramatic 4-3 victory over Lille in Ligue 1 last weekend halted a run of three straight defeats, but PSG's lead at the summit could be cut to just two points should they lose to Marseille in Sunday's derby.
Marseille came out on top against Galtier's side in the Coupe de France last 16 earlier this month, and the PSG boss says it cannot come down solely to key man Mbappe if they are to defeat their closest title challengers and get back to top form.
"Everyone is concerned," Galtier told reporters at his pre-match news conference. "We think that players move on from a defeat in five minutes, but that's not true.
"We will have to win duels to get out of the Marseille pressure. We will have to have more runs in behind, which we lacked during the Coupe de France match. With Kylian, there will be.
"But it's not just him who should help us. He is capable of making a difference, but other players will have to project themselves more freely and with more determination to beat Marseille."
Marseille head coach Igor Tudor stated on Friday that PSG's quality means they are favourites in all of their fixtures, but Galtier disagreed, instead expressing a belief that his team must show improvement over recent form if they are to come out on top on Sunday.
"I cannot say that Marseille are favourites," Galtier explained. "Neither are we.
"For this status as favourites, a different dynamic would have been needed. But the end of the match against Bayern and against Lille gives us a lot of hope.
"We will have to have a very high level of play on a regular basis to beat Marseille, who are in good form and who will be pushed by their fans. We will have to be better than what we have shown in recent weeks."
PSG's poor recent form has reportedly put Galtier under pressure, with former coach Thomas Tuchel linked as a potential replacement should the former Nice boss suffer the same fate as Mauricio Pochettino.
Despite the importance of Sunday's fixture in the title race and the opportunity for PSG to avenge their cup defeat, Galtier does not feel it will be a defining game in his team's season.
"There is no revenge," Galtier added. "There is a lot of pride in this team, obviously that will be important for Sunday evening.
"It's an important match. They are two teams that are very close in terms of the championship with very few points apart.
"Is this decisive for the title? I don't think so."