The Portuguese also revealed that he was "ready" to take charge of England following his sacking as Chelsea manager, while reiterating his desire to return to the Premier League.
The Red Devils travel to Santiago Bernabeu on Feb. 13 for the first leg of the two sides’ last-16 clash as the veteran managers meet for the 15th time.
Mourinho has bettered Sir Alex on seven occasions, losing just twice, but he has never won a Champions League tie at Old Trafford - and the Los Blancos boss is targeting a record 10th triumph in the tournament for his club after admitting retaining their La Liga crown is "impossible".
"The 10th Champions League is a target. But be aware that other teams may well win. We should work a lot for this, and especially this season because we are distanced in the league," Mourinho told RMC. "Manchester United's clash is fantastic. I prefer that. Ferguson is a fantastic example. He comes to see my team and I do the same."
Mourinho has often spoken of his wanting to return to the Premier League following his sacking as Chelsea boss in 2007, and has again reiterated this desire. The 49-year-old did admit that he was close to taking charge of England in 2008, but his commitment to Portugal saw him back away from the opportunity.
"One day, I want to return to England, he said. "I spent only three and a half years and I want to go back. But this is not a priority. Today, I just think about tomorrow's game and that's life for all coaches.
"I would like to coach the national team of Portugal and many people expect it there. I hope to know this experience and play a World Cup or Euro. In 2008, I was ready to take the English team. But for me, it was Portugal that I want, even if you never say never. But England is my first love and it will remain so."