The Argentina international has been criticised for a perceived lack of effort after Barcelona slumped to their third straight defeat on Wednesday
Messi has been under increased scrutiny following Barcelona’s run of three straight defeats, with the latest blow a 2-1 defeat in the Copa del Rey final on Wednesday.
However, Valverde has leapt to the defence of the player and believes it is wrong so much is expected of the Argentina star considering he is always the most marked man on the pitch.
"What interests us is what Messi does Sunday, not what he has done before," said Valverde, talking to reporters.
"The thing is that Messi is asked to pull a rabbit out of the hat every game, when he is the most marked man of all, and that's hard.
"He is not enjoying the form he had before, but he can unbalance a match at any time."
Bilbao sit one spot behind Barcelona in fourth ahead of Sunday’s fixture at Camp Nou, trailing the Blaugrana by 16 points, but Valverde has rejected talk of a crisis in Catalunya.
The 50-year-old added: "You can talk about this change of cycle, but if we cooly analyse their three losses, respecting what Real Madrid, Atletico and Granada did, Barca had options to obtain more positive results.
"What happens is that you judge them in comparison with what they have done these past years.
"We all got quickly accustomed to them winning titles, but did not think about it ending. Accepting defeat is not easy."