A score draw at Old Trafford in the second leg of their last 16 encounter on 15 March would mean United go out.
"A goal away from home is important. We didn't do that, that's a disappointment for me," said United manager Ferguson.
"At this stage of the competition, away goals count. But you have to say at home we have a good chance."
The Scot added that it was a "poor game" for the spectators at Marseille's Velodrome stadium.
"Our passing wasn't as good as it normally is," stated Ferguson.
"Marseille made sure they weren't going to lose a goal. They're very strong defensively, a very powerful team.
"They didn't pose many problems for us. Nothing really happened to be honest and I don't think it was a good match to watch."
It will be a different story in three weeks at Old Trafford but we will have to go there without fear
United's home form ahead of the return leg is impressive, with the Red Devils unbeaten on home turf since a 2-1 defeat by Chelsea on 3 April during the latter part of last season.
Ferguson will be hoping to have centre-back Rio Ferdinand, winger Ryan Giggs and midfielder Anderson available to face Marseille after the trio missed the draw at the Stade Velodrome through injury.
The experience of the Ferdinand and Giggs especially could be crucial, particularly if the French champions have key striker Andre-Pierre Gignac back from the groin problem which forced him to sit out the first leg.
"We will have some players back and whilst we won't be taking anything for granted, this result is fine," added Ferguson
Midfielder Mathieu Valbuena came on as a late substitute for Marseille in the first leg after a month out with a knee injury and his return to full fitness for the second leg will also pose a danger to United.
"Fifty percent of the job is done," said Marseille coach Didier Deschamps.
"It's half the job not to concede goals at home. I'm proud of what my players did tonight because they rose to the challenge.
"We didn't concede, although maybe we should have pushed forward a bit more towards the end of the game.
"It will be a different story in three weeks at Old Trafford but we will have to go there without fear.
"We know the away game is going to be complicated for us but hope is still alive, even if I think Sir Alex Ferguson and Manchester United will be happy with this result."
Source: BBC Sport
Source: BBC Sport