That's despite United's somewhat disappointing season on the pitch. The 'Red Devils' were expected to compete on all fronts this season, but have largely failed to do so, crashing out of the Champions League at the hands of Sevilla and being comfortably beaten to the Premier League title by rivals Manchester City.
Now, the FA Cup is the club's only chance of silverware this season, but they go into Saturday's clash with Spurs at Wembley as outsiders, something that Nicholas does not necessarily agree with.
"If it came down to two teams playing an even game with less on the line then Tottenham win. However, the difference here is Mourinho," he told 'Sky Sports'.
"It will mean more to Pochettino, being his first experience to win something, and he has far more variety and better technical players, who he's improved and advanced as a team.
"This is where Mourinho factor comes into play though, where he knows how to get the result. He will pack his midfield with physical players, perhaps even dropping Paul Pogba again, to ruin Spurs' fluency.
"He did it in the win against Liverpool and when the pressure was on his team turned up. When they needed to step up in the second half against City they managed it."
The Portuguese made seven changes against Bournemouth on Wednesday night in order to rest players, with Nicholas of the opinion that the United boss has prepared well for Saturday's game.
"Mourinho has been preparing his team for these sort of games. He did it with Romelu Lukaku on Wednesday, keeping him on his toes by dropping him, so they're used to operating under pressure," he concluded.