David Moyes' first match as Manchester United manager could be under threat if FIFA decides to sanction the Football Association of Thailand.
United are scheduled to play the Singha All Stars XI in Bangkok on July 13 as they kick off their pre-season tour of the Far East and Australia. Chelsea have also booked a friendly against the same opposition four days later.
Liverpool and Barcelona are also set to play pre-season matches in Thailand this summer.
However, those matches and any other involving teams from outside of Thailand could be blocked after fourth-tier side Pattaya FC won an injunction preventing a vote within the Thai FA over amending their own regulations to put them in line with FIFA's.
The world governing body has warned that a failure to find a resolution by next week could see them banned from international competition.
Outgoing Thai FA president Worawi Makudi, who is a FIFA committee member, told The Nation: "I don't want to speculate on the consequences of a possible sanction but FIFA stated the suspension would prevent us from having international contact.
"I assume it includes everything. [If our] association gets suspended, nobody would want to get involved."
Jaturon Himathongkom, Singha Corp's sports marketing director, added in the Thailand-based, English-language newspaper: "We can't say whether the conflict will affect our matches. What I can say is that, if all the four matches were cancelled due to any reason, would that be fair for the fans?
"They are looking forward to watching these big matches, and all tickets [for the United game] are sold out."
United have also scheduled a match against an A-League All Stars side in Sydney, which could include Alessandro Del Piero, after their Thailand trip before playing two games in Japan.