Simeone wary of 'fearsome' Bilbao
Atletico go into their Copa del Rey quarter-final second leg 1-0 ahead thanks to Diego Godin's goal at the Vicente Calderon last week, but Bilbao have won all but two of their home games since their new stadium's opening in September last year.
Simeone led his side to cup glory last season, but has warned that they will have to perform at their peak if they are to continue defending their crown this term.
He said: "Athletic at home are a strong team and have many variants in attack. They are fearsome.
"The tie is 50 per cent complete. I imagine a very intense game out of which we have to respond.
"It will be a tough, tough game but we have the vision of making a good game where everything is given."
Atletico are 21 games unbeaten in all competitions and have yet to concede a goal in their two previous matches against Bilbao this season.
The winners of the last-eight tie will face the victor of Real Madrid and Espanyol's clash.