Christopher Jullien's positive test after the club’s trip to Dubai saw 13 other first-team players having to self-isolate along with manager Neil Lennon and assistant John Kennedy.
That put Gavin Strachan in charge of a makeshift Hoops side for the 1-1 draw against Hibs at Parkhead on Monday night, and he will be the man in the dugout again for Saturday’s match with Livingston.
But the first-team coach revealed the latest round of tests at the club had all returned negative, and said: "As I understand it, I think it is Monday that [Lennon and Kennedy] are back. I think we have some guys back in on Sunday, and some on Monday, as I understand it.
"They will be assessed in terms of their fitness because they have been off for a little while but they should be available for selection.
"Everyone that was involved on Monday against Hibs and who was in [Lennoxtown] training during the week have all returned negative tests."
Scott Robertson, 19, will be added to the squad, which already contains several other youngsters, after a loan spell at Gillingham.
Strachan, son of former Celtic manager Gordon, said: "Scott Robertson is back in. He is still a young lad but he played nearly 20 games for Gillingham so he is primed and ready to go."But for the most part it is going to be the same guys who were there on Monday. It has been a steep learning curve for most of them.”