Guus Hiddink has refused to make comments on Chelsea January transfer plans amid reports linking them with a move for Leicester City in-form striker Jamie Vardy. The manager, meanwhile, has played down the training "bull threat" incident between Oscar and Diego Costa in the preparation for the FA Cup game with Scunthorpe United, after revealing that Oscar apologised in front of the whole squad for the altercation.

Standard Sport revealed before Christmas 2015 that the technical director Michael Emenalo had identified Vardy as the top target, adding that Jose Mourinho's departure had paved the way for making a move for the £30m ($43m) valued prize asset.

The speculations have increased in recent days following the injury situation at the blues, with both Loic Remy and Radamel Falcao on the sidelines, leaving Diego Costa as the only striker available in Hiddink ranks.

The Dutch boss has admitted his concerns about the shortage of options at his disposal for the FA Cup game with Scunthorpe. However, asked about the potential arrival of Vardy or the rumours linking Eden Hazard with a move away from the club, he said as quoted by Standard Sport: "There are good strikers in this League and abroad."

"Now is the time for speculation to be in the paper over who is going here and there. We won't go into speculation or name anyone, from who we want to who is going to go or whatever."

Meanwhile, on Thursday evening (7 January) it emerged that Oscar and Costa had to be dragged apart by team-mates after the Brazilian provided a reckless knee-high challenge on the striker during a training session. The manager has admitted the altercation but shrugged it off.

"It was a pity that our photographer had the day off because he could have shot two beautiful pictures of bulls who were chesting a little bit after a charge from behind from the smallest bull of the two, which was Oscar," he said.

"He took a charge from behind and it was overdone, especially when you know Oscar – he's not the biggest tackler of the team. He got Diego and of course they then stumbled over the ground, stood up as a normal reaction and chested a bit, without any serious threat of punching or whatever. It was more of a threat of two bulls."

"We came in between, but there is no need to say we had to grab them to avoid them hitting each other. In the intensity of the training session, when it's close to the edge, these things happen."

The Dutch boss, nevertheless, claimed that Oscar himself apologised to his team-mates after the session and the rest of the squad joked about it.

"After that Oscar apologised in front of the group. He wanted to speak, take the podium. He apologised for his overacting and then they started laughing. Jokes were made afterwards. It's a battle that happens when you play with high intensity, it's solved. No disciplinary action. When you control it a few minutes later, it's no problem for me."

The 69-year-old also confirmed his plans to leave the club at the end of the season, once his interim contract expires. He said: "I've put two dates in my mind which is the 25th and 28th May and then it's finished, I can then go home on the 29th.