Mourinho's Real have been irresistible in racking up 10 consecutive wins in all competitions and have opened a three-point lead over second-placed Barcelona with three matches to go before the pair meet in the 'clasico' at the Bernabeu on December 10.
The clashes between the world's two richest clubs by income are generally the key to the league title but third-placed Valencia are one of the few clubs that could have a say in the championship.
Unai Emery's team have finished third the last two seasons, albeit over 20 points short of second place, and are four points adrift of Real after 11 matches.
They held champions Barca to a 2-2 draw at the Mestalla in September and have a point to prove after being humiliated 6-3 at home by Real last season.
"It will be a difficult game to win because they are a team who have taken on board their coach's ideas even more from last time," Valencia stalwart David Albelda told reporters.
"We could be facing the strongest Madrid side of the Mourinho era... but good runs have to end some day."
Real forward Cristiano Ronaldo, fresh from helping Portugal qualify for Euro 2012, emphasised the importance of keeping Barca at arm's length.
POINTS CUSHION
"If we don't beat Valencia or Atletico Madrid [next week] we aren't going to be able to play Barca safe in the knowledge that we have a cushion in case we lose," he told sports daily AS.
"We are doing well, we are better than last year, we are maturing and we want to continue this way."
Ronaldo and Alvaro Arbeloa returned from international duty with minor problems but coach Mourinho could give new signing Nuri Sahin more game time after the Turkey midfielder made his injury-delayed debut in a 7-1 hammering of Osasuna last time out.
Unbeaten Barca are at home to 16th-placed Real Zaragoza on Saturday and after a draw at Athletic Bilbao two weeks ago the champions are in the unfamiliar position of having to hang on the coat-tails of their arch rivals.
Pep Guardiola's side have lacked spark in some of their recent games and have appeared reliant on La Liga's leading scorer Lionel Messi to lift them.
The World Player of the Year, who is still only 24, will take to the Nou Camp eight years and three days after making his first-team debut for Barca at Porto in a friendly.
