Park has struggled to establish himself at Arsenal since arriving from Monaco in 2011, featuring in only six games for Arsene Wenger's side.
The 28-year-old, who spent last season on loan at Celta Vigo, has found himself in limbo at The Emirates after failing to secure a move away from Arsenal during this summer's transfer window.
Park was left out of the South Korea squad for this week's games with Haiti and Croatia - and Myung-Bo insists he has to find a new club if he wants to stay in his plans.
"Park knows what he has to do," said Myung-Bo when asked if he should quit Arsenal," Myung-Bo told the Korea Herald.
"He must find a new team if he wants to remain in the national team."