Celtic have condemned the behaviour of Boli Bolingoli after the defender travelled to Spain on an unsanctioned trip in breach of Covid-19 quarantine rules.
The Belgian defender's action could bring the Scottish football season to a halt after he came on as a late substitute in Celtic's 1-1 draw at Kilmarnock on Sunday.
Now the reigning Scottish Premiership champions have apologised for Bolingoli's actions, saying 'it is difficult to imagine a more irresponsible action in current circumstances.'
The Scottish football season could be halted after Boli Bolingoli (left) travelled to Spain - he was introduced as a substitute in Celtic's 1-1 draw with Kilmarnock on Sunday
The Belgian defender travelled to Spain last week in breach of coronavirus quarantine rules
Celtic boss Neil Lennon - who was unaware of the trip - played Bolingoli as a sub on Sunday
Bolingoli failed to tell Celtic officials he had visited a high-risk country. Anyone arriving back in the UK from Spain has been required to self-isolate for 14 days since July 26.
Celtic manager Neil Lennon was unaware of the player's movements when he brought Bolingoli off the bench late on at Rugby Park.
Scottish First Minister Nicola Sturgeon is set to host a press conference on Tuesday lunchtime with speculation mounting the season could be halted.
In a statement released on Tuesday morning, Celtic expressed regret for the player's 'stupidity'.
It read: 'Celtic Football Club unreservedly condemns and apologises for the behaviour of the player Boli Bolingoli in travelling to Spain without informing the club and in failing to observe quarantine restrictions.
'It is difficult to imagine a more irresponsible action in current circumstances and we find it beyond explanation. The Club will take immediate action through our own disciplinary procedures.
Lennon speaks to Bolingoli before bringing him off the bench in Sunday's game at Rugby Park
'Celtic are in touch with every SPFL club today, and with all relevant authorities, to apologise for the fact that one of our employees has created so much additional difficulty through his actions.
'All of our playing and backroom staff have been tested twice for Covid-19 since this incident and all, including the player in question, have tested negative.sonos sonos