United could be up against Barcelona if they reach the Champions League quarter-finals, but Ferguson is thinking of the Marseille clash and not the Spanish giants.
The Red Devils boss told The People: "Barcelona have produced two performances this season against Real Madrid and Arsenal in the Nou Camp that have captured everyone's imagination and attention and I think every coach will be paying attention to that in particular.
"We have plenty of experience of playing Barcelona because we have faced them a few times at United and I think they know we would be competitive and would have a chance against them.
"Sometimes you can put the fear of death into your players, sometimes when there is no need to and the important thing is to know what your own strength is and we know what we are good at.
"But it's too early to be thinking of playing Barcelona. We're not there yet and it's no good saying you want to avoid this or that, we've got Marseille to worry about first and that's where all our attention will be on Tuesday.
"The first game was a terrible game, a shocking match. I enjoyed the atmosphere in the Velodrome but I didn't enjoy the game and it will be a better one on Tuesday I am sure.
"They'll be planning on how they're going to score a goal and I think they'll try to start the game very quickly, that's a certainty, and we have to be prepared for that part.
"But as the game unfolds, you hope you take your opportunities.
"I went to watch Marseille play in Rennes - who are second in the league - on Friday night to get a better idea of how they play away from home and we've also seen them play at Monaco so we've done our homework."
Ferguson wants a strong defensive display against Marseille on Tuesday.
He added: "The name of the game is to win and I'd be quite happy if it's 4-3 or 1-0.
"We defended well in Marseille and that will be the key again. That's going to be the main element in all of the big games now and after the disappointment of our defending at Liverpool hopefully we'll react that way."