Manchester United midfielder Paul Scholes faces a lengthy lay-off after suffering a knee ligament injury in his side's nil win over Aalborg in their Champions League football match in Denmark.
The experienced former England playmaker missed three months of last season after undergoing knee surgery.
Spain's Villarreal moved level at the top of the group with United after a 1-0 win at home to Celtic.
Arsenal bounced back from their shock loss to Hull in the English premier league with a 4-nil win over Porto,
Real Madrid beat UEFA Cup holders Zenit St Petersburg 2-1 and Juventus drew 2-all with BATE Borisov.
