ROME -- Italian swimmer Gregorio Paltrinieri has contracted mononucleosis, raising questions over whether he'll be able to defend his gold medal in the 1,500-meter freestyle at the Tokyo Olympics due to the energy-sapping virus.
"We're obviously upset because his Olympic preparations were proceeding perfectly," Italian Swimming Federation president Paolo Barelli said Wednesday, adding that Paltrinieri has "minor" symptoms.
"But Paltrinieri is a phenomenal champion and will battle down to the last meter to win the medals he's dreaming about for Tokyo," Barelli said.
Besides the 1,500, Paltrinieri is also planning to enter the 800 free and 10-kilometer marathon races at the Tokyo Games.
Paltrinieri won three golds and two silvers when he competed in both the pool and open water at the European Championships in Budapest in May. He's also a three-time world champion.
Heats for the 800 free, Paltrinieri's first event in Tokyo, are scheduled for July 27.
"He's never given up on anything and with his determination he's won everything," Barelli said. "I'm confident that he'll pull through this time too. He's facing one of the toughest challenges of his career."
Paltrinieri will sit out this weekend's Seven Hills meet in Rome, with the federation adding that he hopes to resume full training "as soon as possible."
If Paltrinieri can't compete, it would leave a wide-open field in the 1,500 with Sun Yang of China having received a doping ban on Tuesday.
Sun won the 1,500 at the 2012 London Olympics then Paltrinieri won the event at the 2016 Rio de Janeiro Olympics.