The pair were said to have come close to blows following a "hefty tackle" in a training session.
Chelsea have had a turbulent season due to taking just 23 points from 20 games in the Premier League and losing their manager Jose Mourinho in December.
News of the bust-up between the two teammates sparked suggestions that the atmosphere in the camp is less than harmonious, but Hiddink has played down the incident.
"It's a shame the photographer was on break yesterday - he could have taken pictures of the two bulls who were chesting a bit," Hiddink told reporters in Friday's press conference. "The little bull took a charge from behind. It was overdone. Oscar is not the biggest tackler.
"They stumbled over the ground, stood up as a normal reaction and chested a bit without a more serious reaction. We came in between but there is no need to say we avoided them hitting.
"We had an intense, very sharp session, it was on the edge. Afterwards Oscar apologised to the team and they started laughing."
Chelsea will turn their attention to the FA Cup third round this weekend when they take on Scunthorpe United at Stamford Bridge on Sunday.