Lionel Messi has benefited from one of the most unusual rules in football - and it is one that would see him banned in any other league.

Messi is back in action on Sunday for Inter Miami's clash with the New England Revolution at the Nu Stadium following a 2-2 draw with Cincinnati on Wednesday.

But a bizarre MLS reason is the reason the eight-time Ballon d'Or winner is available for selection despite racking up a fifth yellow card in his latest outing.

What is the MLS 'Good Behaviour Rule' that Lionel Messi has benefited from?

Messi went into the book for the fifth time, which would ordinarily result in an automatic one-game suspension in every other professional league in the world.

Yet in the MLS, the situation is very different. For a number of years now, the MLS have implemented a 'Good Behaviour Rule’ which applies to all players and not just the face of the league and arguably the greatest player of all time.

Every time a player goes five consecutive games without being yellow carded or finding themselves in any ill-discipline, they have a caution removed from their record. It can reset to zero, with the rule only applying on three occasions. A player cannot have a negative yellow card accumulation.

In greater detail, the official MLS rule states: “A player will automatically reduce his yellow card accumulation total by one yellow card each time he appears in five consecutive matches without receiving a yellow card, red card or supplemental discipline in such matches.

“For clarity, a player cannot have a negative yellow card accumulation total; the Good Behavior Incentive can only reset to a zero-card total. This incentive will be automatically applied a maximum of three times throughout the course of the MLS Regular Season.

“For example, if a player on his third caution of the season completes five consecutive matches without receiving a card or supplemental discipline, that player will have one yellow card caution removed from his cumulative total, leaving the player with a total of two yellow cards.

“The incentive can be applied a maximum of three times during the regular season, and only takes effect once the relevant match has been completed.”

What is the context of the rule for Lionel Messi?

Messi's most recent caution for for complaining to official Armando Villarreal against Cincinnati is technically his fifth but goes down as his third because of the rule.

That's because he had two separate five-game runs of 'Good Behaviour', each reducing his yellow card tally by one.

He had a booking against Orlando City but then behaved for the next five games. After a yellow against Nashville on 15 August, Messi managed to go 10 matches without a yellow before getting booked against Atlanta and then Cincinnati.

Messi's availability is huge for Inter as it means he can play against New England Revolution, who are just two points ahead of the Herons.

A victory for Kily Gonzalez's side will see them climb over their opponents into second place with one game remaining.

Finishing higher will result in higher seeding for the MLS Cup, which Messi is hoping to lead Inter to for the second time.

He is the league's top scorer and on course for the Golden Boot after scoring 25 goals in 29 appearances.