Former Real Madrid boss Carlo Ancelotti says Zinedine Zidane's players need to be more focused and must cut out mistakes if they are to seal the Champions League for the second time in three years, Marca.com reports.
Los Blancos bounced back from a two-goal deficit against Wolfsburg to seal a spot in the semi-finals of Europe's elite competition, but Ancelotti says Real need to avoid a first leg defeat again if they are to get to the finals.
"The Champions League doesn't give you second opportunities," Ancelotti said in a column in Sina Sports.
"If Madrid have to achieve another comeback in the semi-final it is going to be very difficult."
Regarding the Atletico Madrid and Barcelona clash, where Diego Simeone's men ran riot over the Catalans, the Italian said: "It shows once again how difficult it is to defend the Champions League, even if your team has Lionel Messi, Neymar and Luis Suarez."
He also hailed Atleti for their "unity, solidarity and tactical discipline."