Manchester City have instructed their lawyers to take action after striker Carlos Tevez failed to report for training on Wednesday.
The club expected Tevez to attend the session, despite him being pictured arriving in Argentina on Tuesday.
City said Tevez had been refused permission to return home.
He flew to South America on the day it was reported he would not contest a misconduct charge relating to an incident in a match at Bayern Munich.
Most of City's players are away on international duty but Tevez, who has not played since the 2-0 Carling Cup win over Birmingham in September, was due to remain in Manchester to continue his personal training programme.
The forward was not selected for the Argentina squad for the fixtures against Bolivia and Colombia, to be played in the next week.
Tuesday was a scheduled day off, but Tevez was expected back at the training ground on Wednesday morning.
And, after his client was pictured in Argentina, the player's spokesman, Paul McCarthy, told Sky Sports News: "He's gone to see his family.
"We've said all along that Carlos is aware of the situation in terms of getting back to his fitness. I can't really say much more until he's back in the country."
City had found the former Manchester United striker guilty of committing five breaches of contract in a Champions League game against Bayern in September.
Manager Roberto Mancini wanted to bring Tevez on as a substitute with 35 minutes left but he refused to warm up.
He was immediately suspended for two weeks and had a four-week fine halved after the intervention of the Professional Footballers' Association.
After allowing Tuesday's deadline for an appeal to pass, it had been anticipated that Tevez's improved relations with the club would allow a smooth departure, either on loan or on a permanent basis, in January.
It is understood that Tevez believes a move away from Etihad Stadium in the next transfer window is his best option.