Vidal is expected to be confirmed as a Barca player upon the successful completion of a medical after a €20m deal was agreed between the two clubs, FourFourTwo magazine reported.
At 31, the former Bayer Leverkusen and Juventus star is approaching the latter stages of his career.
But Barca coach Valverde expects the Serie A, Bundesliga and Copa America winner to compliment the less combative players in central positions.
"He's a player who we hope will bring energy to the midfield," the boss said.
"He has a lot of experience and has played a lot of games on all the teams he has appeared with. He's accustomed to playing in big matches.
"He has a lot of presence on the field and I think that will be very good for us."
Many observers will consider Vidal to be an improvement on Brazil international Paulinho, who has returned to Guangzhou Evergrande just one season after a surprise switch to Camp Nou.
"Like Paulinho, he's a player who's a little bit different than the ones we have and we think he will be able to adapt well," Valverde said.
"He's a warrior. Our team has space for many different types of players.
"Last year there was a little bit of controversy when Paulinho came, and before he even played a single minute. Then people saw that he worked out really well."
Questioned about Barca's other potential transfer activity, Valverde said, "We are trying to enrich our team.
"We are FC Barcelona and, like any other club, we are open to improving our team.
"We don't know what might happen before the end of the transfer window."