Arsenal captain Laurent Koscielny has refused to travel with the squad for its preseason tour to the United States, the Premier League club said on Thursday.
The 33-year-old French center-back has one more year on his contract and British media reported that Ligue 1 clubs Girondins Bordeaux and Olympique Lyonnais were interested in signing him.
"We are very disappointed by Laurent's actions, which are against our clear instructions," Arsenal said in a statement. "We hope to resolve this matter and will not be providing any further comment at this time."
Koscielny, who joined Arsenal from French side Lorient in 2010, has made over 350 appearances for the London club.
Arsenal is set to play the Colorado Rapids, who are also owned by the club's majority shareholder Stan Kroenke, on Monday before facing Bayern Munich, Fiorentina and Real Madrid in the International Champions Cup.