Premier League, according to his father.
The South Korean midfielder joined the Super Hoops from Manchester United in a £2m deal last summer, and has endured a tough spell in London.
His stint at Loftus Road has been blighted with injuries, limiting him to just 22 appearances.
During his brief playing time he has been helping the club in their battle against the drop, but has been unable to drag them from the foot of the table.
His father, Park Jung-Song, says that the toils of this season have effected his son, and confessed the could consider quitting the sport:
“Nobody knows the future, but I think he has made his mind up to retire. He thinks he’s played enough,” he is quoted by The Metro.
“He’s never had times like this with PSV Eindhoven or Manchester United. My son has had difficult times at QPR this season; it was a new experience to him.
“Ji-Sung said it’s difficult to keep his feel for the game as his playing time is inconsistent, but he doesn’t have any hard feelings.”
The 32-year-old retired from international football in 2011, in a bid to prolong his club career.
He is set to discuss his future with manager Harry Redknapp at the end of the season.