Chelsea players Oscar and Diego Costa in training ground scrap as Chelsea tensions boil over

Pair have to be separated by team-mates at Cobham after Brazilian’s ‘robust’ challenge on combustible Spanish striker

Chelsea’s Diego Costa, left, and Oscar remain ‘best friends’, according to the latter, but accusations of disharmony have dogged the team this season (Getty)

Tension between senior members of Chelsea’s first-team squad have erupted with team-mates forced to separate Oscar and Diego Costa following a training ground clash between the two players.

Although Brazilian midfielder Oscar and Spain forward Costa are understood to have stopped short of exchanging blows while preparing for Sunday’s FA Cup third-round tie against Scunthorpe, the pair had to be pulled apart after Costa reacted angrily to what has been described by witnesses as a “robust” challenge by Oscar.

Costa, who has done little to diminish his reputation for seeking confrontation on the pitch during his 18 months at Stamford Bridge, is understood to have been provoked into a reaction by fears that Oscar could have inflicted a serious injury with the tackle. But while there was a heated exchange between the two players, sources close to the incident have insisted that frayed tempers were quickly eased and that Oscar and Costa were joking about the clash at the end of training.

Chelsea have refused to comment on the incident, but interim manager Guus Hiddink will address the matter at his press conference on Friday.

The Dutchman, who replaced the sacked Jose Mourinho last month, is believed to accept that the bust-up at Cobham was nothing more serious than two players displaying creative tension and that incidents of that sort happen regularly on training grounds up and down the country.

Oscar tried to downplay the incident by taking to social media. “For those who are talking to me and @diegocosta struggle today in training he’s lying, he’s one of my best friends and never fight,” he wrote.

However, with the Chelsea squad subjected to accusations of disharmony this season and allegations – strongly denied – that one player would “rather lose than win” for Mourinho, the spat between Oscar and Costa will lead to further scrutiny of team unity at Stamford Bridge.

Chelsea’s captain, John Terry, claimed, “That player wouldn’t be let out of the dressing room”, in response to the allegations of a team-mate wanting to lose, but after Mourinho’s sacking, the defender admitted that the club could have sacked a number of players rather than the manager.

“If it was the case where you could get rid of a lot of players, I’m sure clubs would do that,” Terry said. “But unfortunately it does fall on the manager’s head.”

Both Costa and Oscar are expected to be involved in the squad to face Scunthorpe this weekend, despite the incident, but the ongoing involvement of striker Radamel Falcao is uncertain.

Falcao, on a season-long loan from Monaco, suffered a fitness setback last week after a two-month thigh injury lay-off and the Colombian returned to his parent club earlier this week, prompting speculation in France that he may be set to cut short his deal at Chelsea.

It is understood that Falcao, who scored just four goals for Manchester United during an awful loan spell at Old Trafford last season, spent two days at Monaco’s training base earlier this week in order for the club to assess the state of his injury. He returned to Cobham in order to continue his rehabilitation, but the prospect of him returning to Ligue 1 this month has not been discounted.

Chelsea are prepared to allow Falcao to terminate his loan deal, with the 29-year-old scoring just once for the club this season. Monaco, who have appointed former Chelsea midfielder Claude Makélélé as technical director, remain wary of cancelling the player’s loan transfer, however, due to his £330,000-a-week wages at the club – a salary more than double the amount Chelsea have paid the striker this season.

With Costa and Loïc Rémy ahead of him, Falcao appears unlikely to get much playing time with Chelsea. He is open to a move back to Monaco and he has already rejected interest from clubs in Mexico and Turkey in order to return to France, where his contract expires in 2018.

Meanwhile, Chelsea have loaned out Brazilian full-back Wallace to Gremio until June 2017. The 21-year-old spent the first half of the season in Serie A with Carpi.

Friendly fire: Other training ground bust-ups

Martin Skrtel v Luis Suarez Came to blows over a game of head tennis at Liverpool’s Melwood complex in 2014.

Dani Osvaldo v Jose Fonte Southampton striker banned for two weeks and later had contract terminated after headbutting team-mate in 2014.

Mario Balotelli v Roberto Mancini Involved in confrontation at Manchester City’s training ground in 2013, over a tackle on Scott Sinclair. Forward also clashed with Micah Richards, Jérôme Boateng and Vincent Kompany.

Andy Carroll v Steven Taylor Carroll broke Taylor’s jaw at Newcastle United’s training ground in 2010.

Ousmane Dabo v Joey Barton Barton attacked his Man City colleague in 2007 and was later charged, resulting in a suspended prison sentence.

John Hartson v Eyal Berkovic Hartson kicked the midfielder in the face at West Ham’s training ground during a fracas in 1998.