Messi, seeking a fifth Ballon d'Or crown later this week, finally committed his long-term future to the Catalan club last week by agreeing a new four-year deal.
Having scored 17 times in all competitions this term, the 30-year-old was left on the bench for the opening hour of Barca's 2-0 win over Sporting Lisbon on Tuesday night, and Rakitic believes that it is important Valverde continues to look after the superstar forward.
"The important thing is that he's happy here. The important thing is that he's with us and he's by our side," he told reporters. "Sometimes he should rest.
"To play with him is always special and when he has 20 to 25 minutes too he can change the game and the play completely. It's good that he was good in this game and we have to look after him well."
Thirteen of Messi's goals this term have come in La Liga, putting him well clear at the top of the scoring charts.