Florentino Perez's shock resignation from the Real presidency on Monday has rocked the club as he pointedly called into question the squad's commitment to the cause.

Disillusioned home fans will be keen to make their point after third-placed Real slipped 10 points behind Primera Liga leaders Barcelona last Sunday after a lacklustre 2-1 away defeat to Real Mallorca.

New president Fernando Martin was crystal clear with his views on the players on Thursday when he demanded 100 percent effort from each and every player.

"Those players who think they can stay here only giving the minimum amount of effort are wrong," said Martin.

"I'm not afraid to take tough decisions if people don't give their all for this club."

Real's six-match winning run in the league came to an end last weekend against a side who showed a greater fighting spirit and willingness to compete.

Their next opponents, ninth-placed Atletico, have shown similar traits in turning round their season recently, and come into the game with their tails up after six straight victories.

But Atletico are wary of how Real's players will respond to recent events.

Midfielder Peter Luccin told sports daily Marca: "We know they are going through a difficult moment and we hope to profit from that.

"We don't fear them but we know they will be keen to give their all to try and win back the support of their fans."

While Atletico appear to hold a spell over league leaders Barcelona they have consistently failed to rise to the occasion against Real of late.

They have not beaten Real since returning to the top flight in 2002.

Atletico have injury doubts over Argentine trio Maxi Rodriguez, Ariel Ibagaza and Luciano Galletti.

Real have defender Sergio Ramos suspended while Guti is struggling to recover from a thigh injury. Coach Juan Ramon Lopez Caro may look to rest players ahead of next week's Champions League clash with Arsenal in London.

Barcelona, who hold an eight-point lead over second-placed Valencia, have home advantage against an unpredictable Deportivo La Coruna on Saturday.

With their two closest rivals dropping points last weekend while they beat Real Zaragoza 2-0 away, Barca believe the title is theirs to lose.

"Barcelona's main rivals are Barcelona," goalkeeper Victor Valdes told the club website.

Depor, who are seventh, beat fourth-placed Osasuna 2-1 away last weekend but have Argentine defender Fabricio Coloccini suspended.

Valencia can extend their unbeaten run in the league to 15 games when they visit bottom club Malaga on Sunday.