The 1978 World Cup winner is confident the prolific attacker will get back his best form in Braziil this summer
The 26-year-old attacker has received his fair share of criticism in recent months, despite scoring 28 goals in 31 La Liga appearances.
However, Menotti is convinced that Messi will shine at this summer's World Cup in Brazil, arguing that a return to South America is just what the four-time Ballon d'Or winner needs.
"I think Messi is going to come right back to the source, to the neighbourhood with his family and get away from the maelstrom," Menotti told Sport.
"In Barcelona there is a lot of pressure and I think this has made him suffer.
"He needs to depart that climate and return to his natural place with his family, be with his friends and start training with the national team.
"It's the logical way for recovery. I think he'll go to the World Cup very well.
"Coming to Rosario and training with the team before travelling changes everything. Already it's a new world, where he is well-liked and highly respected."
Menotti also refuted the suggestion Messi was not playing whole-heartedly in their final Liga game, which saw them draw 1-1 with Atletico Madrid to hand the latter the title.
"He looked sad on the field, but he wasn't saving himself," he insisted.
"When a footballer enters the pitch for the final league game he wants to be the best and win. It's an emotional thing."