Souleymane Diawara has admitted that anything other than a win against Brest tomorrow will be a disappointment.
The Senegal defender has been buoyed by Marseille's Champions League exploits against Inter Milan, which sees them take a 1-0 advantage to the San Siro.
However, Diawara said that his team did not have long to celebrate their momentous first-leg victory at the Stade Velodrome.
"We were happy with this win but we did not have time to enjoy it because we have an important game at Brest on Sunday," the 33-year-old told France Football. "We absolutely must get three points if we want to catch up with the top three.
"We lose a lot of energy competing in the Champions League, but we must try to forget about the fatigue. We go to Brest to win. To draw 0-0, that would be a disappointment."
Diawara said that he is not getting carried away by Marseille's slender advantage against the Nerazzurri, but added that anything can happen.
"I'm not going to get too excited by saying we'll win the Champions League, but we will do everything to achieve it. In football everything is possible."
Diawara moved to Les Phoceens from Bordeaux in 2009 for a reported fee of €7m (£5m).