French international Payet refused to play for West Ham in order to get a 30 million euros ($32 million) move to Olympique Marseille.

The 29-year-old hero of France's Euro 2016 campaign showed little regret over reports that he had to give back Â£500,000 (580,000 euros/$625,000) in wages for the January games missed before West Ham finally let him go.

Ulloa branded the strike threat after demanding that English champions Leicester City's manager Claudio Ranieri let him leave.

"I feel betrayed by Ranieri and let down by the club. I will not play again for them," he said on Twitter ahead of the final day of football's horse-trading. Ulloa has struggled to get a first team place this season.

With the stakes so high, other players also decided on a go-slow to pressure their clubs. Julian Draxler dragged his feet at German side Wolfsburg after one transfer request was rejected last year until he signed for Paris Saint Germain on January 1.

No respect

And they are not the first. Since George Eastham went on strike in 1959 at Newcastle United over a rejected transfer to Arsenal, it is a tactic that has been regularly used.

"You cannot compel a player to play for you. You cannot get an injunction to force your player onto the team bus," said Chris Lynn, a labour and employment lawyer at Squire Patton Bloggs in London.

But he said even a fine would not make much difference "considering the modern football salary."

Lynn said football clubs are at a major disadvantage compared to ordinary companies.

"Usually, an employer can simply dismiss an employee who is refusing to carry out their duties or the inherent threat of such a dismissal will prevent an employee refusing in the first place."

"It is not so simple for a football club" as players are clubs' most valuable assets as they seek playing success and build up commercial revenue through image rights, shirt sales and potential transfer fees.

West Ham could not dismiss Payet for refusing to play because it would then not be able to sell him, the lawyer said.

"The clubâs equivalent of recruitment costs will also be rather more painful than the ânormalâ employer given they will likely need to buy a replacement for a potentially large transfer fee."

"The easy route is to simply accept the playerâs position and sell him, but then the club sets a precedent for the future which it is unlikely to want. Any player who wishes to move will simply go on âstrikeâ as per Payet, knowing the club will likely avoid the fight and simply cash in."

West Ham co-chairman David Gold slammed his former French player, saying "Payet did not show the same commitment and respect to West Ham United that the club and fans showed him."

"With a number of top Premier League players holding clubs to ransom is it time to close the January transfer window?" Gold said in a recent Twitter comment as the showdown with Payet mounted.

Yet despite West Ham's protests, club manager Slaven Bilic has also acknowledged that insisting they did not want to sell Payet was part of their campaign to get a higher price.

Bilic and co-owner David Sullivan vowed throughout January that they would not sell Payet for any price.

But Bilic acknowledged: "That was part of the the tactics. It was obvious from the day I announced it openly that he would go and we wanted the best price possible, of course.

"I want to thank him for everything he did for us - he was brilliant last year. We were brilliant for him also. Now that story's finished I wish him luck and all the best in Marseille."

M. Doria

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