Lionel Messi's continued presence in the MLS with Inter Miami has opened the eyes of a whole generation of European football fans to the organisation of the sport in the USA.

This season, the Argentina international has picked up five yellow cards that ought to leave him suspended for yellow card accumulation, but the league's 'Good Behaviour' rule is set to ensure that he is available for selection against New England Revolution.

The 39-year-old is set to be spared by the lesser-known league provision active since 2007, sparking widespread social media backlash.

What is the MLS 'Good Behaviour' rule and how does it work?

Under standard disciplinary frameworks across most major European and international leagues, accumulating five yellow cards triggers an automatic one-match suspension.

Messi received his fifth booking of the campaign on matchday 32 of the MLS season against FC Cincinnati, leading many to assume that he would automatically miss the subsequent high-stakes Eastern Conference clash against the New England Revolution.

Instead, Major League Soccer's Good Behavior incentive came into play to spare the blushes of the eight-time Ballon d'Or winner, ensuring that Inter Miami will have their talisman available this weekend.

The incentive, which was introduced 19 years ago, was made to reward disciplined play from among the MLS players.

Under this incentive, if a player completes five consecutive matches without receiving a yellow card, red card, or additional disciplinary sanction, one booking is automatically deducted from their accumulated total.

Messi has already fulfilled the requirement on two separate occasions this season, meaning that two previous yellow cards from his total had already been wiped out.

As a result, he is now on just three bookings and will not face a suspension for card accumulation in the regular season this year.

'MLS is not a serious league': Fans mock MLS for incentive

The latest information regarding Messi's suspension or the lack of it has led to widespread mockery and ridicule for the MLS on social media.

The league had already been viewed as being of significantly lesser quality by European fans, and the new situation provided them with an opportunity to make fun of it on social media.

One fan argued that the league is soccer, not football, and has no standard rules. “America doesn’t play football, it’s soccer. Naturally no standard rules applies there.”

Another fan was bemused at the notion that a player on good behaviour received five separate bookings. “So, a guy who gets 5 yellow cards is good behavior? Don't mess with me”

A fan asked that a whole other sport be established for North America. “Just create a whole new sport for North America”

Another fan simply stated that the MLS is not a serious league. “The only league in the world with a rule like that, MLS is not a serious league”

Despite the rule being applicable to all players in the MLS, news of Messi's clearance ignited intense ridicule across social media platforms.

Rival supporters and online football commentators have questioned the timing and optics of a regulation that conveniently preserves star power for teams.

Ultimately, Messi was cleared to lead Inter Miami onto the pitch, keeping his pursuit of a second successive MLS Golden Boot alive.