Smith was at Leeds when they faced financial meltdown and he said: "This isn't a crisis. Leeds was a crisis."
After losing against Blackburn a fortnight ago fans booed boss Sir Alex Ferguson for his tactics and they only just beat Fulham 3-2 last week.
Smith added: "Manchester United have always had winners and it's fair enough that people expect us to win matches.
"This is nowhere near the crisis at Leeds, but for Manchester United it is not a good situation.
"You see who your characters are in these situations. You see the players who go out there and give it all.
"The fans here have been used to success for years and they're disappointed when they don't get it. That's only natural. We've got to be big enough to get over it.
"We need to keep winning. There's loads of talk about Chelsea this and Chelsea that.
"At the end of the day we've got to stop worrying about Chelsea. We get to play them twice in the season and those games are the only chance we get to have an effect on them.
"The rest of the time all we can do is focus on ourselves."