A well organised side who play attractive football under Argentine coach Eduardo Berizzo, Celta surprised champions Atletico Madrid 2-0 at their Balaidos stadium in February and held out until 17 minutes from time at home to leaders Barcelona this month before falling 1-0.
With Real depleted by injuries to Gareth Bale, Karim Benzema and Luka Modric, and possibly still feeling the effects of their exertions in the Champions League on Wednesday, ninth-placed Celta have an excellent opportunity to make a mark against the world's richest club by income.
"If we needed the points it would be different but we are going into the match with all the calm in the world and with the maximum desire to make things difficult," Celta defender Andreu Fontas told a news conference on Wednesday.
"Physically we are in spectacular shape for this stage of the season and mentally we are in a good place after securing our place in the top flight," said the centre back.
"I am sure that Real Madrid will avoid both relaxing or thinking they can win without getting off the bus.
"But they know that if they don't compete at 100 percent Celta can cause them problems."
Second-placed Real, who are two points behind leaders Barca with six games left, could find themselves five points adrift of their arch rivals if Barca can win at neighbours Espanyol on Saturday.
Coach Luis Enrique may rest some of his regulars after Barca secured their place in the Champions League semi-finals with a 2-0 win at home to Paris St Germain on Tuesday.
Atletico, meanwhile, four points clear of fourth-placed Valencia in third, need to pick themselves up for Saturday's game at home to Elche after Real knocked them out of Europe's elite club competition on Wednesday.
Third place carries a berth in the Champions League group stage, while fourth secures a spot in qualifying.
At the other end of the table, Cordoba, at the bottom and five points behind Granada, can boost their slim chances of avoiding the drop with a win at home to King's Cup finalists Athletic Bilbao on Friday.

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