Cesc Fabregas said it is difficult to imagine "humble" Lionel Messi ending his long association with Barcelona – and claimed Cristiano Ronaldo is an inspiration for players over 30.

Fabregas will be a keen observer of Barcelona's Champions League fixture with Juventus on Tuesday, which is set to revive the longstanding rivalry between his friend Messi and Ronaldo.

Monaco midfielder Fabregas was a team-mate of Messi's during his rise through Barca's La Masia youth academy and played alongside him in the first team between 2011 and 2014.

The pair won LaLiga, the UEFA Super Cup, Club World Cup, Copa del Rey and Supercopa de Espana together during Fabregas' stint with the Blaugrana.

Argentina forward Messi, 33, has been at Barca for two decades but rumors overs his future persist with his contract due to expire next year.

When asked if he thinks Messi will remain at Camp Nou, Fabregas struggled to contemplate the prospect of him playing elsewhere.

"Barcelona is his home," Fabregas said in an interview with Tuttosport. "They have been his team since he was little [but] they are very personal choices, I don't interfere.

"What I myself often say to him: 'Leo, you don't realize how big you are''. Messi does not really have the perception of being a God of football, he is a very humble, sunny boy.

"He loves to live like normal people so much that, despite being a star, he would like to move without the security men. He also has a great heart, he is always ready to help sick children and the poorest people."

The 33-year-old acknowledged that Juventus forward Ronaldo, 35, is an inspiration for all players as they reach the twilight of their careers.

Messi and Ronaldo have previously met in five Champions League encounters, with Messi 3-0 up on Ronaldo in goals. 

The game on Tuesday would be their first duel in the competition since the May 2011 semi-final between Barcelona and Real Madrid and the first with the Portuguese in a Juventus shirt.

"I don't know Cristiano personally, but everyone tells me that he is super professional and has an incredible mentality," Fabregas explained.

"It will no longer be the CR7 that jumps over players with his dribbling, but he still scores a lot. I hope to reach the age of 36, so that I have a 20-year career.

"Now it is less complicated than in the past because we players have more information and we manage ourselves better: from rest to recovery, to nutrition.

"For example, I never drink alcohol and carbonated drinks. The only time is a beer on vacation!"

Fabregas also revealed he nearly moved to Serie A before he left Chelsea for Monaco in January 2019.

"I was close to three Italian teams before coming to Monaco," Fabregas added.

"I spoke with [Carlo] Ancelotti, when he was coaching Napoli, and also with [Ivan] Gazidis, when he moved to Milan. But I preferred to choose Monaco."