Marcelo mystified by Isco's refusal to take Real Madrid captain's armband during shock CSKA Moscow loss

The Spain international also appeared to angrily confront the whistling home supporters during Wednesday's defeat

Real Madrid defender Marcelo admitted that he is at a loss to explain why Isco declined to take the captain’s armband from him during Wednesday’s shock 3-0 home defeat against CSKA Moscow.

The reigning European champions, having already secured their position as winners of Group G with a game to spare, suffered their heaviest-ever European loss at Santiago Bernabeu.

Isco cut a frustrated figure throughout the match and, when Marcelo went to hand him the armband as he left the field to be substituted in the second half, appeared to decline the honour.

“I tried to give the armband to Isco [when I came off for Dani Carvajal],” Marcelo confirmed after the game. “But he told me that I had to give it to Carvajal. I don't know what the reason for that was.”

Goals from Fyodor Chalov, Georgi Shchennikov and Arnor Sigurdsson secured a famous win for already-eliminated CSKA, while Madrid were roundly whistled by their own fans.

Real Madrid suffered their heaviest-ever home European defeat against CSKA (Getty)

Isco was singled out when he appeared to turn to the crowd and shout, “What do you want?” after seeing a shot deflected behind by a CSKA defender early in the second half and confronting referee Artur Soares Dias to remonstrate with the official about his decision not to award a corner.

“I didn't see Isco's reaction,” Marcelo added. “But I don't think it was against the fans. We're here to give our all for this club.

“We're really hurting, but all we can do is recover and focus on the weekend [against Rayo Vallecano in La Liga].”

Madrid lie fourth in La Liga, five points adrift of leaders Barcelona, having lost five of their first 15 matches of the season and conceded 19 goals.

They are also on their second coach of the campaign, with former player Santiago Solari replacing Julen Lopetegui in October in the wake of a humiliating 5-1 Clasico defeat against Barcelona.