Co-owned by former Manchester United, England and Real Madrid star David Beckham, Inter Miami lured Matuidi from Serie A champions Juventus to the United States for their inaugural season in 2020 – the World Cup-winning star teaming up with Gonzalo Higuain after the club used targeted allocation money (TAM).
But MLS deemed Inter Miami were not roster compliant in March – meaning the team effectively had four designated players last season rather than the three allowed.
Following an extensive investigation on Friday, Inter Miami's violations were found to include the incorrect roster categorisation for Matuidi and Andres Reyes – who should have occupied a designated player slot. The violations also included undisclosed agreements that resulted in the underreporting of salary budget amounts for players Leandro Gonzalez Pirez, Nicolas Figal and Julian Carranza.
As a result, Inter Miami – along with the stiffest fine in league history – had a reduction of $2,271,250 in allocation dollars for the 2022 and 2023 seasons, while managing owner Jorge Mas was fined $250,000 and former sporting director Paul McDonough received a suspension through the 2022 campaign and he subsequently departed Atlanta United.
"The integrity of our rules is sacrosanct, and it is a fundamental principle of our league that our clubs are responsible for adhering to all league regulations," said MLS commissioner Don Garber.
"Our rules will not be compromised. These sanctions reflect the severity of Inter Miami's violations, should encourage complete cooperation by all parties in future investigations, and will serve as a deterrent for clubs from violating roster rules."
The investigation also found no wrongdoing on the part of Inter Miami owners Marcelo Claure, Masayoshi Son, Jose Mas, and Beckham.
In a statement, Mas said: "Inter Miami CF acknowledges that the club violated Major League Soccer's roster rules in our first season.
"We have worked closely with MLS to address these issues and have made significant changes in our management structure. Following our inaugural season, we took a deep look at our soccer operations leadership group and made decisions that not only strengthened our internal roster compliance measures, but also better positioned us to build a sustainable, long-term competition strategy with the hiring of Chris Henderson as chief soccer officer and sporting director in 2021.
"Inter Miami is an ambitious club with big aspirations. We believe our fanbase, market and ownership group propel us to be one of North America's most-followed futbol teams in the world. We are committed to supporting our team and building a roster we are proud of."
Inter Miami – led by head coach Phil Neville this season – are ninth in the 14-team Eastern Conference with eight points from seven games in 2021.
Matuidi is the second Juve to be diagnosed with the virus after Daniele Rugani was confirmed as their first case last Wednesday.
Like Rugani, Matuidi's test has come back positive despite the player not developing any symptoms; however, he had already been in isolation since his team-mate's diagnosis.
A statement released by Juve read: "Blaise Matuidi has undergone medical tests that have revealed his positivity to the coronavirus-COVID-19.
"The player, as of Wednesday March 11, has been in voluntary home isolation. He will continue to be monitored and will follow the same regime. He is well and is asymptomatic."
Football in Italy is suspended until April 3 due to the pandemic, but Italian Football Federation (FIGC) president Gabriele Gravina has already suggested it is not realistic to expect action to resume at the start of next month.
Euro 2020 was due to start in Italy's capital Rome on June 12, but on Tuesday the tournament's postponement until June 2021 was confirmed by UEFA.
No country outside China has been more heavily affected by the virus.
COVID-19 was declared pandemic last week and has affected 196,000 people worldwide, with just under 32,000 cases recorded in Italy, where 2,503 deaths have occurred.
Rugani was among the first wave of high-profile confirmed cases in Serie A when he tested positive for COVID-19 last month.
Matuidi followed as Juve's second case, although neither player developed symptoms.
A month on, the duo have each returned two negative tests.
The Bianconeri's statement read: "The players have, therefore, recovered and are no longer subjected to the home isolation regime."
The duo have not missed any action as Serie A has been suspended amid the pandemic.
The Italian Football Federation (FIGC) is looking to resume the season in the coming months, however.
FIGC president Gabriele Gravina has praised Juve for their apparent stance against being awarded the Scudetto as they top the table at the time of the pause in play.
Maurizio Sarri's men are a point clear of second-placed Lazio with 12 matches remaining.
It was confirmed on Saturday that Argentina forward Dybala is the third Juve player after Matuidi and Daniele Rugani to contract COVID-19.
Dybala said he and his girlfriend Oriana Sabatini have tested positive but both were in good condition.
Matuidi took to Twitter on Sunday to offer a message to Dybala.
"Keep shining bright like a joya hermano [roughly translated as jewel brother]," he posted.
Serie A remains on lockdown amid the coronavirus pandemic, with Juve top of the table.
Italy has been the worst-affected nation in terms of deaths, with 4,825 having died.
Inter Miami lured Matuidi from Serie A champions Juventus to the United States for their inaugural season in 2020 – the World Cup-winning star teaming up with Gonzalo Higuain after the club used targeted allocation money (TAM).
But as Inter Miami prepare for their second season in MLS, which kicks off under Phil Neville against LA Galaxy on Sunday, MLS deemed the club were not roster compliant – meaning the team effectively had four designated players last season rather than the three allowed.
Higuain, Rodolfo Pizarro and Matias Pellegrini were Inter Miami's listed designated players in 2020.
"The league has concluded that Inter Miami was not in compliance with the roster and budget rules during 2020," a statement read on Friday, with the league to finalise its investigation and sanctions in the "near future".
"In 2020, Matuidi was categorised as a targeted allocation money [TAM] player. Matuidi's compensation was above the compensation limit for a TAM player and he should have been classified as a designated player.
"As a result, Inter Miami CF violated the designated player limit as the team had three designated players in addition to Matuidi during 2020."
To become roster compliant, Inter Miami exercised their off-season buyout on midfielder Pellegrini – one of last season's designated players.
Pellegrini – signed from Argentine side Estudiantes ahead of the 2020 campaign – joined the club's USL League One affiliate Fort Lauderdale CF on loan and will not be eligible to play on the team's 2021 MLS roster.
"We've been working with Matias, his representatives and MLS to reach an agreement, and at this time we believe this is the best option for all parties," Inter Miami sporting director Chris Henderson said.
"Matias is a talented young player with an exciting career ahead. He will remain with the organisation as we work on finding an on-field opportunity and next steps for him."
Inter Miami endured a tough time in 2020, finishing 10th in the Eastern Conference before losing in the play-in round of the playoffs.
They also suffered three defeats in three games in Group A of the MLS Is Back tournament amid the coronavirus pandemic.
The 34-year-old former Morocco captain played a part in five consecutive league championship wins, firstly when landing two Bundesliga titles at Bayern in the 2014-15 and 2015-16 seasons.
He joined Juventus from the German giants and featured in each of the next three campaigns as the Turin giants mopped up successive Scudetto triumphs, also leading his country at the 2018 World Cup.
Benatia was born in France and began his career in the Marseille youth set-up. He shot to prominence after a move from Clermont to Udinese in 2010, which paved the way for a switch to Roma in 2013, and one year later he was prised away by Bayern amid a scramble by elite clubs for his services.
After a double-winning second season, Benatia moved on to Juventus in 2016, before leaving the Bianconeri to sign for Qatari outfit Al-Duhail midway through the 2018-19 season.
While at Juventus, he was part of the squad that reached the 2016-17 Champions League final and also won the Coppa Italia twice. Most recently he has been with Turkish Super Lig side Fatih Karagumruk, who said Benatia had retired because of injury.
Responding to Benatia's announcement, which he revealed on Instagram, Juventus striker Paulo Dybala sent a heart emoji to his former team-mate. Ex-Bayern winger Franck Ribery did likewise, with current Juve full-back Juan Cuadrado and former favourite Sami Khedira also among those that sent greetings.
Blaise Matuidi, the former Juventus and France midfield general, wrote: "What a career, my brother. I remember those days at [French national football centre] Clairefontaine where we began to dream of being a professional footballer, but by dint of work you did much more than that. Incredible clubs, captain of a nation and having won a good number of titles, you can only be proud brother."
Manchester United defender Eric Bailly joined in the praise, writing: "Bravo capitano. Great man, great career, very good player and finally an example."
Paris Saint-Germain full-back Achraf Hakimi praised his former national team skipper, with the message: "Capitanooo. Good luck in your new stage big bro."
Announcing his decision to retire, Benatia said: "From a young age I had only one dream, to become a professional footballer. To get there, I had to force myself to work hard, make sacrifices, but above all set new goals at each stage of my career.
"This job has also allowed me to defend and represent my country, Morocco, with whom I have experienced unforgettable moments... in particular the 2018 World Cup."
The Manchester United midfielder's long-term future appears uncertain, with his former club Juve one of the teams heavily linked with the World Cup winner should he depart Old Trafford.
Pogba spent four seasons with the Serie A champions between 2012 and 2016 before returning to United for what was a world-record fee at the time.
In a video uploaded to his Instagram account on Wednesday, Pogba was seen training at home wearing a Juve shirt with Blaise Matuidi's name and number on the back.
However, the Frenchman explained that he and United team-mate Victor Lindelof - who was spotted in Albin Ekdal's Sampdoria jersey - were simply supporting their international team-mates after both Serie A players tested positive for coronavirus.
"New training camp is called... Quarantine PP Arena, open 24/7!" Pogba wrote on Instagram.
"Having fun working at home with my brother @victorlindelof.
"Supporting our friends @blaisematuidiofficiel and @albinekdal and all athletes and people around the world!
"Be strong, #StayAtHome and be safe!
"(I know the cheeky ones will talk about the Juventus jersey [but] I'm just supporting my friends... that's all, nothing more)."
Matuidi replied to Pogba's post by saying: "Thank you my brother this touched me love u.
"And glad to see you touch the ball."
Pogba has not played for United since December 26 having undergone surgery on a right ankle injury in January.
He was due to return to team training on Tuesday but United cancelled their session after the United Kingdom government urged citizens to avoid unnecessary travel and social contact.
