The former South Korea captain has struggled since leaving Manchester United last summer, and he may step down after the conclusion of his current contract in what will have been a career lasting 14 years.
"My son has had difficult times at QPR this season; it was a new experience to him," the elder Park said in an interview with Sports Chosun. "He's never had times like this with PSV Eindhoven or Manchester United.
"Nobody knows the future; maybe he could play one more year with a new team after next season. But I think [Ji-Sung] has made his mind up to retire."
Park, who turned 32 last month, began his career with Japan's Kyoto Sanga just months after making his national team debut.
After winning the 2002 Emperor's Cup with Sanga, he captured two Eredivisie titles with PSV before a trophy-laden seven years with Manchester United that included four Premier League wins and the 2008 UEFA Champions League crown.
Despite his son being one of Asia's most popular players, Sung-Jong denied that Park would return for a victory lap in his native country before hanging up his boots.
"He won't play in the K-League," Sung-Jong said. "He wants Korean football to be popular but he wouldn't be able to perform well.
"He thinks he's played enough."