Eddie Hearn has tested positive for Covid-19 ahead of Joshua Buatsi's bout with Marko Kalic on Sunday.
Matchroom Boxing chief Hearn said he left the secure bubble "immediately" on receipt of his positive test result.
Buatsi will take on Kalic for the WBA international light heavyweight title on Sunday in Milton Keynes.
Hearn insisted he was the only person to test positive in the wider camp building up to the fight to be staged at Stadium MK's Marshall Arena.
"Gutted to just find out I tested positive for Covid-19 today and have to leave the bubble immediately," Hearn posted on Twitter.
"Thankfully all other tests were negative. Heading home to rest – catch up tomorrow."
