Leganes struck twice in a minute to claim a 2-1 win on Wednesday, although Barcelona remain top of the table ahead of Saturday’s game with Athletic Bilbao at the Camp Nou.
“When you lose then you are open to any kind of criticism,” Valverde told www.marca.com.
“It doesn’t bother me if one thing or another is pointed out. I want to have the best team in order to win.
“In terms of a lack of attitude, my team has a fantastic attitude. Everyone makes mistakes – myself and the players.
“Whenever a team lets in two goals in a minute it is an accident, but we have to improve – that is clear – and it is the same when you win.
“We have looked at why we didn’t attack better after scoring, and these are things which are not explainable. It is difficult to explain why they scored two goals in a minute and then we struggled to respond.”
Barcelona will be without defender Samuel Umtiti against Bilbao due to a knee injury, while Gerard Pique could be rested against the 15th-placed Basque side.
“We will see if we make some adjustments,” Valverde added.
“That doesn’t mean that we will change the whole approach. When we look at the team, we know we are a side with quality players and I don’t think the system is so important.
“We need to deal with the game tomorrow knowing that it will have characteristics which are different to those we have faced up to now.”
Bilbao have not won at the Camp Nou since 2001, but despite their current lowly league position they have suffered just one defeat from five outings this season, while winning one game and drawing three.
And head coach Eduardo Berizzo is set to welcome back striker Aritz Aduriz following his recovery from a thigh injury, and he has been named in the squad.
Dani Garcia and Markel Susaeta are also back, with Bilbao looking to buck recent history and end their losing run on Barcelona soil.
“It is Barcelona, a team full of great players and a great coach. For us, it is a maximum test,” Berizzo said, in comments posted on Bilabo’s official Twitter feed.
“There are not so many occasions in life in which you can play in Camp Nou, so it is a privilege.”
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