Messi came off the bench to spare his side from defeat against Sevilla last weekend, helping his side rally from a two-goal deficit to grab a draw, and played the full 90 minutes in the midweek Champions League win over Roma.
Valverde decided against resting his star player for the La Liga clash with Leganes on Saturday – and watched on as the club's all-time leading scorer bagged a treble.
"We think he's fine and scoring goals always helps everything," Valverde said of Messi's health after the game at Camp Nou.
"He has to be active, but he's fine."
Valverde also singled out Ousmane Dembele for special praise, believing the Frenchman is now not only making a difference offensively but also developing an appreciation for his defensive responsibilities.
"I liked the way he attacked in that game," he said. "I also enjoyed the fact that he has pressed the ball so much after losing it.
"He has become involved in that facet, which is where I think he has more room for improvement.
"We know he has the talent, but he has to work at the other things."
Barca's victory over Leganes saw them equal Real Sociedad's record of 38 top-flight Spanish matches without defeat, a run that stretches back to April 2017.