Xavi was part of a golden era alongside Messi under Pep Guardiola at Camp Nou, claiming 25 trophies with the club before departing for a new challenge with Al Sadd.
Messi's status as a global phenomenon is unquestioned and he has enjoyed an illustrious domestic career, winning eight LaLiga titles, four UEFA Champions Leagues and five Copas del Rey with Barca.
However, it has been a story of heartbreak for Messi with Argentina, losing three Copa America finals and missing out on 2014 FIFA World Cup glory to Germany.
Messi has often come under scrutiny for failing to replicate his sublime Barca form with his country, but Xavi says both sides must make the most of their prized asset.
"Barcelona and the Argentine team can't afford to spend even 10 minutes of the match with Leo not getting possession of the ball," Xavi said in an interview with Mundo Leo.
"He has to be wherever it goes and if he's not there, bring it to him. [Otherwise] he's going to get p****d off.
"Messi is the one that will make things happen for the team."
Argentina only occupy a play-off spot in the CONMEBOL section of 2018 FIFA World Cup qualifying and host Peru before visiting Ecuador as they bid to clinch a top-four spot that will punch a ticket to Russia.
While their campaign has been underwhelming, Xavi believes Jorge Sampaoli, who took over as head coach in May, can lead Argentina to FIFA World Cup glory.
"I see them being very capable of winning a World Cup next year," he continued.
"It is true that now they are in a difficult situation, which is the qualification in South America.
"But we will all agree that if they qualify for the World Cup, they must be one of the favourites based on their players and now because I think they have the right coach. Everyone appreciates Sampaoli in Spain."