Real Madrid captain Iker Casillas says they must finish the season strongly after this week's Champions League heartbreak.

Casillas has urged Jose Mourinho's star-studded squad to bounce back and turn their seven-point lead over Barcelona into silverware.

"It has been a harsh blow and it's hard to get back on our feet, but we must carry on and focus on what remains of the season," said the Spain international.

"Penalty shoot-outs are like the lottery and we lost due to bad luck. That's all there is to it."