Juventus coach Massimiliano Allegri says they cannot afford any errors against Champions League opponents AS Monaco.

The first-leg of the quarterfinal kicks off tonight.

"We're playing for the semi-final of the Champions League, we have a great deal of respect for our opponent," the Coach told Sky Italia.

"Monaco has the best defence in the French League, and only conceded one goal in the group stage.

"We'll need patience and concentration, they have a great mix of youth and experience and have eliminated Arsenal, Benfica and Zenit [St Petersburg].

"Sometimes we'll have to take a few more steps to get to goal, and make as few mistakes as possible, because over 180 minutes, if you make mistakes you'll be heavily punished."