The former Inter Milan coach believes that because the Eredivisie has got underway over a month ago, Ajax could be fitter than Real.

Los Merengues have only played two La Liga matches so far this season.

"I am not at all relaxed heading into Wednesday because it is the Champions League and Ajax have already played four matches in the competition and ten official games in total," Mourinho said.

"They should be somewhat more fit that us."

Real have been widely criticized of late for their lack of cutting-edge but Mourinho insists the Spanish giants are still likely to defeat Ajax at Santiago Bernabeu.

"Despite the fact that we have had trouble building plays, finishing and picking out the rhythm of matches, we are the favorite and we must win because it is crucial to get off to a good start in the Champions League," The Special One added.

Egyptian striker Mido has rejoined Ajax on a free transfer in the summer and is yet to play his first competitive game with the Dutch side this term.

The 27-year-old once said he wants to make his first appearance against Real in the anticipated Champions League meeting.