Casemiro snubs Alejandro Garnacho when naming the four players who are 'heirs' to Lionel Messi and Cristiano Ronaldo

The debate over Lionel Messi and Cristiano Ronaldo and their status as two of the greatest footballers of all time is well worn. As they start to age out of the spotlight, the discussion has moved on to their successors.

Manchester United midfielder Casemiro is one player who is well positioned to take a view on the matter. The Brazilian has played with Ronaldo more than 100 times for Real Madrid and Man Utd, and against Messi on no fewer than 20 occasions.

As a former Real man and a Brazilian international, Casemiro also knows a thing or two about the players coming up in the wake of the greats.

But his Man Utd teammates didn't get a look in when Casemiro told Diario AS the four players he considers the 'heirs' to Messi and Ronaldo in years to come.

Kylian Mbappe tops Casemiro's tips for greatness, as reported by the Mirror.

"[Mbappe] is one of those players that when you play against them you don't know how to stop him. He's not [on top of] the podium yet, but he'll get there," he said.

"He's the heir to [Messi and Ronaldo], along with Vinicius Jr, who continues to grow and improve in every game, Rodrygo, and Fede Valverde."

Mbappe reminded the football world of his exceptional talent with a Champions League hat-trick to knock out Manchester City earlier this week.

Casemiro's quartet of Madrid superstars unsurprisingly includes Vini Jr as well as fellow Brazilian Rodrygo and Uruguayan midfielder Valverde. They're all in their mid-twenties and delivering on the pitch at the biggest club in the world.

Kylian Mbappe scored three to knock Manchester City out of the Champions League at the Benabeu. (Image: Getty)

There's no room on Casemiro's list for Alejandro Garnacho. The United winger is one of the few players likely to get through this season at Old Trafford with his reputation relatively unscathed but Casemiro clearly doesn't think 20-year-old Garnacho's potential lives up to the extreme standards of his idols – at least not yet.

Garnacho has started just 14 Premier League games for United this season, scoring three times. His limited use has been scrutinised by United supporters, who have seemed against his potential departure as the club seeks to offset its allowable losses under the Premier League's profit and sustainability rules.