Oscar de Marcos is confident Athletic Bilbao are in a 'great position' to knock out Manchester United as coach Marcelo Bielsa is making the players believe they can beat any team in the world.
Bilbao secured a thrilling 3-2 victory at Old Trafford last week in the first leg of the Europa League last 16 and host United at San Mames in the return on Thursday.
De Marcos scored Bilbao's sumptuous second goal against the Premier League leaders, but then gave away a late penalty which allowed United to claw back a goal.
However, De Marcos is feeling upbeat ahead of the visit of the Red Devils and outlined the philosophy that Bielsa has instilled in the players.
"The coach is putting it in our heads that nobody is better than us, that we can compete with any team and we did that against one of the best teams in the world," said De Marcos in the Daily Mirror.
"The key thing [in the first leg] was we had the ball the whole game. It's our philosophy, as the manager has taught us, to keep the ball and thanks to this we created a lot of chances."
De Marcos was disappointed with the handball which allowed Wayne Rooney to score from the penalty spot, but he remains optimistic that Bilbao can reach the quarter-finals.
He added: "It's clear 3-2 keeps them in it more, and unfortunately it was my handball.
"It was a shame after all the work the team put in, but we have to be happy with the result. Before we came, everyone would have taken a win at the Theatre of Dreams and we know we are in a great position."