The Scottish champions say Christopher Jullien was the player to test positive for Covid-19 on return from the club’s Dubai training camp.
A local NHS health protection team has since deemed 13 other players to be close contacts.
Manager Neil Lennon and assistant John Kennedy must also isolate.
All 15 members of staff will also be absent for Saturday’s Scottish Premiership trip to Livingston.
Celtic stress that injured defender Jullien was the only positive case, saying they are “hugely disappointed” by the decision.
But First Minister Nicola Sturgeon urged Celtic to “reflect seriously” on events that have led to the recent outbreak.
“I know that what I’m about to say wont please everyone, nothing I can say about football ever pleases everyone, but as I have said before, I do have doubts based on how the club itself described it, doubts about whether Celtics trip to Dubai was really essential,” she said.
“I have doubts based on some pictures I have seen about whether adherence to bubble rules was strict enough.”
Jullien is the fifth Celtic player to test positive for Covid-19, with David Turnbull, Odsonne Edouard, Nir Bitton and Hatem Abd Elhamed previously contracting the virus while on international duty.
On Saturday, Celtic assistant manager John Kennedy admitted the club had been guilty of “minor slip-ups” in Covid-19 protocols during their six days in Dubai.
Photos emerged of members of the Celtic party not distancing or wearing face coverings, and Kennedy says they give a “bleak” but “false” impression.
“The contacts were identified during the period from Wednesday last week, primarily around flight and team coach travel, during which time Celtic applied the same rigorous protocols used for pre-season training camps, Uefa match travel and for all domestic match arrangements in Scotland,” read a statement from the Scottish Premiership champions.
“These protocols have served us well in the past, as the club has not had one positive case in our own ‘bubble’ until now. As we have already stated, Celtic’s decision to travel to Dubai for a training camp was for performance reasons. Whilst we were in Dubai, the announcements made on 4 January significantly changed the COVID landscape.
“The reality is that a case could well have occurred had the team remained in Scotland, as other cases have done in Scottish football and across UK sport in the past week.”