Suarez returned to Montevideo early Friday, arriving too late to see the president of Uruguay and hundreds of fans who had gathered the previous night to give him a hero's welcome despite his World Cup banishment.

In Rio de Janeiro, FIFA secretary general Jerome Valcke said a third biting incident in Suarez's career was "unacceptable."

"I think he should find a way to stop doing it — he should go through a treatment," Valcke told reporters at Maracana Stadium, where Uruguay plays Colombia in a Round-of-16 match on Saturday.

The players' union, FIFPro, came to the same conclusion but from a more sympathetic approach.

FIFPro said the FIFA disciplinary panel's ban for Suarez of nine Uruguay matches and four months from all football "infringes his right to work" and doesn't offer him the treatment he needs.

"Luis Suarez should receive all the support he needs to deal with any off-field issues he may be experiencing at this time," the union said, adding that "treatment must be a part of any sanction."

Neither Valcke nor FIFPro specified if the treatment should include anger management therapy or counselling.

From Italy, Suarez also received support from his latest victim, Giorgio Chiellini, who described the sanction as excessive.

It was a view shared on Friday by Uruguay coach Oscar Tabarez, who has quit his role in FIFA's strategic committee in protest at the length of the ban.

Tabarez blamed English-speaking media for creating pressure on the FIFA disciplinary panel to punish Suarez and said that FIFA seems to have "values very different from those that I have."

In his first public comments on the controversy, FIFA President Sepp Blatter declined to discuss the length of the ban but condemned Suarez's action.

"It is not fair what he has done," Blatter in a video interview on FIFA's website, which was recorded Friday before Tabarez spoke.

Suarez bit Chiellini's left shoulder during Uruguay's 1-0 win over Italy at Natal on Tuesday. The incident went unpunished by the referee but was broadcast around the world on TV.

It was the third time Suarez has bitten an opponent, after incidents in the Dutch and English leagues. He was banned for seven and 10 matches, respectively.

"If it starts to be more than once it is not any more an (isolated) incident, so that is why also the sanction has to be exemplary," said Valcke. "I applaud the decision."

"What happened with Suarez was beyond the game, was something which is far beyond the fair play and the attitude you can have when you play at the World Cup," the French official said.

Still, FIFPro said the sanctions should be reduced, calling on FIFA's appeals panel to "focus especially on the accumulation of sanctions."

"The fact that Suarez is prohibited from working for a long period must be addressed as it directly infringes his right to work," the Netherlands-based union said in a statement.

FIFPro suggested that a legal review could "re-establish the facts in a calm and considered setting."

The Uruguay football federation is preparing an appeal to FIFA, which Suarez's club Liverpool is not involved in.

If FIFA dismisses Suarez's appeal, a further legal challenge is allowed at the Court of Arbitration for Sport in Lausanne, Switzerland.

CAS could freeze the sanctions upon request, allowing Suarez to resume training and playing for Liverpool during the appeal process.

Chiellini, a veteran Italy and Juventus defender, wrote in a blog for website Sportlobster such a long ban could be "really alienating" for a player.

"At the moment, my only thought is for Luis and his family, because they will face a very difficult period," Chiellini said.