The Australian international has been linked with a move to the Far East and will not be considered for Thursday's Edinburgh derby with Hibernian.
McGlynn said: "The club have accepted a bid for Ryan so he won't play any part in the game tomorrow.
"He's not put pen to paper. It's disappointing to lose him but if good offers come in we need to accept them."
McGowan's agent, Lou Sticca, said: "Ryan will be on his way to China to talk to a leading club there within 48 hours, with the full permission of Hearts.
"A transfer fee has been agreed in principle and it's a matter of Ryan having a look around and considering personal terms.
"There has been interest from a number of clubs but the offer from China is the one Ryan is looking at most closely."
McGowan, who came to Hearts seven years ago, is one of several players entering the final six months of their contracts and, with the club in financial difficulties, McGlynn faces the prospect of many first-teamers departing in the January transfer window.
As well as McGowan, fellow defenders Andy Webster and captain Marius Zaliukas are out of contract at the end of the season.