Ernesto Valverde defends Gerard Pique after sending off

Valverde's team played most of the match with 10 men after Pique was sent off two minutes before half time in Wednesday night's 3-1 win at the Nou Camp.

The defender was booked early on for a cynical pull back on Vadis Odjidja-Ofoe and he received a second yellow card when Scottish referee Willie Collum decided he tried to deliberately score with his hand from a Gerard Deulofeu cross.

"Pique? I haven't seen the replays, but I'd imagine it was all instinct, with the goal so close to him," Valverde told reporters after the game.

Pique's dismissal came with the score at 1-0 after a Dimitris Nikolaou own goal had set the five-time European champions on their way to a third straight win in Group D.

Despite their numerical advantage Olympiacos were unable to cause Barcelona problems and Lionel Messi took the game away from them in the space of three second-half minutes. First scoring with a lovely curling free-kick and then teeing up Lucas Digne for the third goal.

"We knew they'd get stronger once we went down to 10 men. That's why we needed to find a second goal, so things would become easier," said Valverde.

"They came to defend and find a goal on the counter-attack. With our opponents playing so deep, it was tough to find rhythm and they played a game that suited them.

"But he (Messi) splits the game up and looks for players to link up with. When he's heading towards goal, he always looks for team-mates to finish off his moves."

Nikolaou went part way to atoning for his own goal by heading a consolation goal at the beginning of injury time for the group's bottom club, who are yet to win a point.