Marseille captain Mamadou Niang has told his players they must defeat rivals Paris St Germain this weekend or face slipping out of the title race.
OM have failed to find their best form so far this season and back-to-back draws have stranded them in mid-table, six points behind leaders Bordeaux.
Didier Deschamps' side threw away a golden chance to make inroads on the pacesetters last time out when they conceded three goals in the last 10 minutes away to second-placed Lyon to draw 5-5.
That has piled the pressure on OM ahead of the visit of their bitterest of rivals, in a match postponed from last month when three PSG players contracted swine flu.
"We are motivated because we have the desire to redeem ourselves following the draws against Toulouse and Lyon," Niang told OM's official website.
"We did not lose but we are not moving up the table either. It would be nice to start a series of victories, starting with Paris on Friday.
"Unfortunately, we did not win the match in Lyon, which was within our reach. That would have helped narrow the gap to Bordeaux.
"We must not lose ground by losing this match - we must take maximum points."
Bordeaux, who are a point ahead of Lyon, will look to preserve their perfect home record when they welcome Valenciennes on Saturday.
The leaders have made an excellent start to the season - they have also qualified from their Champions League group - although they lost their most recent league encounter 2-0 at Lille.
"I think we have made a very good start to the championship," midfielder Fernando Menegazzo told Bordeaux's official website.
"We have had two or three losses that could have been avoided, but it's hard to be very consistent throughout the season. We will try to erase these mistakes to continue the path to success."
Second-placed Lyon have won just one of their past four league games but will be firm favourites to beat rock-bottom Grenoble - who claimed their only point of the campaign at Monaco a fortnight ago.
In-form Auxerre have climbed to third on the back of six consecutive wins and will host fourth-placed Monaco at the Stade Abbes-Deschamps while Rennes round out Saturday's fixtures at home to second-from-bottom Le Mans.
On Sunday, Lille will look to build on their surprise win over Bordeaux when they travel to Montpellier while Nice can claim their fourth win on the spin at home to Toulouse.
In the final game of the round, fifth-placed Lorient travel to St Etienne.
