The former Chelsea manager may have scooped the La Liga title last season but after a disastrous league campaign this time around only European glory can salvage his reputation.
The Spanish giant takes on Manchester United on Wednesday at the Santiago Bernabeu in the first leg of their Champions League last 16 tie against the Premier League leader.
|MOURINHO'S REAL MADRID RECORD
"A 10th European title is absolutely huge for the people of Madrid and for Mourinho too," McManaman told Goal.com.
"It would seal his reputation if he can win his third Champions League at three different clubs and confirm him as a success everywhere he’s been.
"It would be a very successful three years if he wins the Copa del Rey in his first season , La Liga in the second  and then the Champions League in the third.
"Mourinho is without doubt one of this new breed of super-managers along with Pep Guardiola.
"I think, whatever happens, he will leave Real Madrid before the start of next season and I’ve seen he’s been linked with Chelsea, City or Paris Saint-Germain so it will be interesting to keep an eye on that."
McManaman won two Champions League titles during four years at Real Madrid and can relate to the current side's troubles in La Liga as he recalls his team's poor domestic form in both campaigns, finishing only fifth in 2000 and third in 2002.
"Especially in 2000, the Champions League was our savior because we had a terrible season in the league," McManaman said. "They can put all their effort into the Champions League now and they are certainly a much better team than Chelsea were last year - they only finished sixth in the Premier League.
"I think Madrid will get past United but there are so many great teams in the Champions League. I would like to see them win it but it will be very difficult. Mourinho likes that kind of challenge though and in Cristiano Ronaldo they’ve got a player who is out of this world.
"You have to fancy him to score against United but that’s hardly a bold prediction because he’s got an unbelievable record and scores every week."
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