Chelsea manager Guus Hiddink has described a training-ground clash between Oscar and Diego Costa as "two bulls who were chesting a bit."

Commenting Friday on an incident that was widely reported in British media, Hiddink said the two players squared up to each other after Oscar tackled Costa from behind during an intense practice session, and needed to be separated.

"They stumbled over the ground, stood up as a normal reaction and then chested a bit without any further seriousness of threat of punching or whatever," Hiddink said of an incident that took place Thursday.

Hiddink said Oscar apologized in front of the squad, and that Oscar and Costa "looked at each other and started laughing."

Both players were born in Brazil.

"We had an intense, very sharp training session and it was close on the edge," Hiddink said. "These things happen ... I think it's OK. Jokes have been made (about the incident) after."

Hiddink is in charge of Chelsea until the end of the season following the firing of Jose Mourinho a week before Christmas.

The temporary reign has started well, with Chelsea unbeaten in three games under the Dutchman, but Hiddink said he definitely won't be taking over on a permanent basis.

"I think we have made it very clear that at the end of this (interim spell), then I will stop," he said.

Chelsea plays third-tier club Scunthorpe in the third round of the FA Cup on Sunday.