LaLiga chief Javier Tebas has claimed Manchester City could not sign Lionel Messi on his previous Barcelona terms without the aid of "financial doping".
Messi is now a free agent after his contract at Barcelona expired on June 30 and the Catalan club's current financial problems are hindering their attempts to re-sign him.
That has led to speculation clubs such as Premier League champions City, who were heavily linked with Messi last summer, or Paris St Germain could step in.
Tebas, a long-time critic of City, claims it would not be legitimately possible for the English club to sign him, on a deal matching the player's previous salary, given their losses during the coronavirus pandemic.
Speaking at a press conference, the president of the Spanish top-flight competition said: "He won't be able to sign with the same conditions of the former contract, that would be absolutely impossible.
"I don't think any European club would be able to pay that amount – not just Barcelona. I don't think any club would be able to pay that amount of his former contract.
"If City have lost 270million euros, obviously they wouldn't even consider signing up Messi, and PSG have had big losses – they just can't take into account signing up Messi.
"If they do it, then they will continue to do what I say – it will be the financial doping.
"I told (City manager Pep) Guardiola this too, and I directly said that to him – would you have won as many titles without as much economic doping?
"When the CAS (Court of Arbitration for Sport) let off Manchester City, there were a lot of comments about that – (Jose) Mourinho and all these other coaches said this. So, if this happens, I really think it would be absolutely incredible that it would happen.
"So this is the sort of governance where we should establish minutes. This economic doping in football is what is really damaging football.
"It inflates the salaries, it means that there is non-real money that is involved, because it is not generated by the club.
"So if the money in the football industry isn't generated by football, it just causes inflation, and it's a bad type of inflation that just ruins football because then the clubs have to put in all this effort that is well above their financial capacity. They just have to look at their sports capacity.
"We need to really fight against this, and we will continue to do this all the time. I think this is one of our pending issues in European football and if it's not solved soon, it could lead us to a very complicated financial situation in European football."
The PA news agency has approached City for comment.
Tebas claims Barcelona need to save four euros for every euro they spend. Huge savings would therefore need to be made to accommodate Messi.
He admits losing Messi, 34, would be a blow to the competition but is confident it could be overcome.
He said: "If Messi leaves, obviously it will affect us, obviously our competitors will be happy about that.
"But we will continue to work along the same lines that we work today. We have suffered Ronaldo leaving and Neymar leaving.
"Let's see what happens with Messi. There's still time to go. As far as I know, he hasn't signed up with anyone else, so I still think that today he is closer to Barcelona than other teams."
Barcelona were one of 12 rebel clubs to sign up for the controversial breakaway European Super League competition in April.
The ill-fated venture collapsed within days amid a wave of protest from across the sporting and political spectrum but Tebas accepts the matter will probably return in another guise in the future.
He said: "The project that was presented specifically this April has failed but the actual Super League concept, which at the end of the day is that the big European clubs dominate and decide and manage, that's always existed, and will exist, because that's the dream of Real Madrid and a few other clubs."
