Casemiro warned his Real Madrid team-mates they must tighten up at the back ahead of a mouth-watering Champions League showdown with Paris Saint-Germain.
The Liga champions' title defence in Spain suffered a further blow on Saturday when they were held to a 2-2 draw away at lowly Levante, Giampaolo Pazzini marking his debut for the hosts with a dramatic late equaliser.
Unlikely to make up a massive 18-point gap on runaway leaders Barcelona in the league and already out of the Copa del Rey after a shock defeat to Leganes, Zinedine Zidane's side will see Europe as their best chance to claim silverware this season to add to August's Supercopa de Espana title.