Kylian Mbappe has reportedly reported his former club Paris Saint-Germain to UEFA, with his actions potentially having huge ramifications for the Champions League. The 25-year-old left the Parisian club for Real Madrid in the summer, with no transfer fee attached to the deal as his contract had expired.

The departure was anything but acrimonious, with PSG club bosses angered at the notion of getting no return on the £153million they paid Monaco back in 2018.

According to French outlet Le Monde, the French striker is now also unhappy at proceedings, believing he is still owed around £4.2m from the Ligue 1 club in unpaid bonuses and wages.

Mbappe is said to have contacted UEFA with his complaint. If the organisation decides to investigate and subsequently charge his former club, they could face severe penalties.

The most extreme sanction could see them booted out of the Champions League for the 2024/25 campaign. This year's version of the tournament is set to be the most lucrative yet for participants, amid a new format and expanded number of teams.

Mbappe is also said to have contacted the Ligue de Football Professionnel (LFP), the governing body for French domestic football. His actions will inevitably have angered the club's owners, QSI, who already face a sizeable task to rebuild the club after his exit followed the departures in 2023 of Lionel Messi and Neymar.

Mbappe signed his last contract with PSG in 2022, a two-year deal worth a reported £61m before tax. That was supplemented by a staggering signing-on fee of £127m, plus loyalty bonus payments of £59m for the first year and £68m for the second year.

His deal at Madrid runs until 2029, and is worth around £12.8m a season. He was also handed a plus a £128m signing-on bonus to be paid over five years, and will also keep a percentage of his image rights.

But his start to life in Madrid has got off to a mixed start. He scored on debut in the European Super Cup last Wednesday, helping his side to a 2-0 win over Atalanta.

But he turned in an ineffective display in his side's 1-1 draw at Mallorca on Sunday. Manager Carlo Ancelotti refused to dig out his new striker afterwards, but was clearly unhappy with the team's performance.

"We lacked balance," he said. "I am not happy with the draw because we could have done better. We need more attitude. We can learn a lot from this game because it seems clear where we could have a problem."