Barca crashed out of the Champions League after surrendering a 4-1 first-leg lead to Roma, who won 3-0 on Tuesday to progress on away goals.
It was a night to forget for Messi and the Liga leaders in the Italian capital but Barca head coach Valverde said his team cannot dwell on the result ahead of Valencia's visit on Saturday.
"Messi is like his team-mates," Valverde said. "We are a bit sad and low but we have to face this challenge and want the ball moving again. That's how it is.
"Messi is one of the players who has won more Champions League's during his career. Winning the UCL is really difficult, only one team can win it, so it's very difficult.
"You cannot have a bad moment in this competition and that happened to us the other day."