Neymar played under the 58-year-old during his time with Santos before completing a big-money move to the Camp Nou in the summer.
Despite a promising start, the Brazilian has struggled to hit top form in recent weeks and Ramalho has criticised his Spanish club for their preference towards Messi.
"He seems sad to me. The team seems to be playing for one man only. These were the concerns I had about him going to Europe. He is sat on the bench," Ramalho told TV Globo.
"Against Manchester City there were two passages of play in which Neymar was free but Messi didn't pass him the ball. He will finish being the best player in the world in a year and a bit.
"Messi is still at his peak and Neymar is preparing to be the best with patience. He is on the right track to do it."
Ramalho is currently in charge of Sao Paulo.