Whenever I start a new season there is a very clear-cut goal, which is that Barcelona would do its best," said the Argentine wizard, who recently agreed a three-year contract extension at Barca.
"Personally I am very happy and looking forward to starting the new season," added the newly wed Messi as Barcelona celebrated a new sponsorship deal with Japanese e-commerce firm Rakuten at its Tokyo headquarters.
"It's a new beginning. Everything will be new (under Valverde). We are hearing a lot about his very good reputation so we will just do our best."
While Messi avoided making bold statements for the new campaign after fierce rivals Real Madrid stormed to the La Liga and European Champions League titles last season, Barca team-mate Arda Turan said:
"It's important that we are going to win all the titles this year -- we can do it."
They were joined by Neymar and Gerard Pique for the media event with Rakuten founder and chief executive officer Hiroshi Mikitani.
"The objective is always to win, whether or not I score goals," said Neymar.
"We are a team," added the Brazilian. "If I can score goals obviously I'll be happy, but with Pique and Messi, and the other players score goals that's also good. As long as the team wins I'm happy."
Valverde replaces Luis Enrique, who stepped down at the end of a successful three-year spell in charge of Barca.
Rakuten's four-year sponsorship deal, worth €55 million ($63 million) a year, will last through June 2021, with the option of a one-year extension.
The e-commerce giant replaced Qatar Airways, Barcelona's shirt sponsor since 2013.
Rakuten signed the deal as it seeks to expand overseas.
The company already owns J-League side Vissel Kobe and professional baseball team Rakuten Golden Eagles.