Barcelona coach says Frenkie de Jong will add some fresh energy to the side's midfield after returning for preseason this week.
De Jong is one of three signings made by the club so far this summer. Antoine Griezmann and Neto are the other two.
Barça paid Ajax 75 million euros for De Jong, who won a double with the Dutch club last season and helped them reach the Champions League semifinal.
"They are three important signings," Valverde told Barça TV. "Each one in his own way. We expect a lot from them. They know the fans are excited and what we want them to do now is get into team dynamic as fast as possible.
"De Jong is a A player who last year, and in recent years, has been at a high level. He had a great year last year, his whole team did, and we hope he can give us some fresh energy in midfield, which can only be good for us.
"We are also building for the future and he has years ahead of him. He is a quality player and we know he has a bit of our playing style about him."
On a general note, Valverde added: "The players have come back in good shape, picking up rhythm, and are very focused.
"This preseason is different from previous preseasons. We have less time before the tour in Japan. Last year, we had more of a margin. This year, we have our first matches after less training sessions but the players are looking good."