Real Madrid captain Iker Casillas admits he has been impressed with the progress made by city rivals Atletico Madrid this season.
Atletico are second in La Liga, eight points clear of Real ahead of the Madrid derby on Saturday.
And Casillas believes his side will have to dig deep to beat their city rivals and close the gap in the table.
While Atletico have never beaten Real this century, Casillas believes Saturday’s derby looms as something different.
“It’s clear that it will be a different derby compared to others in recent years,” Casillas said.
“Atletico are coming to the Bernabeu in great form.
“They are coming into the game having beaten Seville, a team that saw off a Betis side that beat us last Saturday.”
Atletico have not won at Real’s home, the Bernabeu, since 1999 but that was also the last time Madrid’s second-largest club went into a derby higher on the table than their city rivals.
Casillas believes one man has made the difference at Atletico.
“(Diego] Simeone’s arrival at Atletico has given the club a lot of stability,” Casillas said.
“The attitude has changed there and they are where they are on merit.
“The numbers back that up, both in the cup, although they still have a match to play, in Europe and in the league.
“They are coming into the fixture in excellent form and I think it will be a great game.
“I just hope for the fans that we can get a win on Saturday to make up for the defeat against Betis.”