Messi announced last week that he would be staying with the Catalan giants for another season despite handing in a transfer request last month.
During the ongoing saga, the Argentine forward initially refused to join up with the rest of the team for pre-season but has since returned to training and was spotted with the squad earlier this week.
Messi's conduct throughout the period has been questioned by some, but Valdes believes that his former teammate is beyond reproach.
"I have suffered during this because he is my colleague," Valdes told RAC1. "Leo was with me since making it to the first team and I've always had a strong connection with him.
"I have suffered because the attitude of Leo cannot be questioned, nor his qualities. I've been hurt by the comments but we know this exists in football. I am very happy that Barca can keep him and I hope he can give many happy moments to them.
"I think it'll be a good season for him. We will see the Leo who can show what he's capable of. It's guaranteed he can be decisive in every game, that's the most important thing."