Park was banned for 18 months by governing body FINA after testing positive for testosterone ahead of the 2014 Asian Games, and while the ban expired in March he must now wait three more years before he can be considered for selection under KOC rules.
Despite the ban, Park decided to compete at last week's national trials anyway and won the 100m, 200m, 400m and 1 500m freestyle events. He swam the fourth fastest time of the year in winning the 400m, clocking 3 minutes, 44.26 seconds.
The 26-year-old, who won gold in the 400m freestyle at the 2008 Beijing Games to become the first Korean to win an Olympic swimming medal, told a news conference at Incheon City Hall on Monday he wanted the chance to make amends for his mistake.