Greg Taylor has arrived out of Kilmarnock for an undisclosed fee to Celtic at Parkhead ahead of the move.
The two clubs agreed a fee to get its left-back on Monday.
Taylor has had his medical as parties try to finish a deal ahead of the midnight deadline.
The Scotland trained using the group on Monday afternoon before a breakthrough has been made between the two clubs.
It’s understood defenders Jack Hendry and Calvin Miller won’t move as part of their offer to Kilmarnock.
League One Bolton had made a enquiry to get Hendry but could not find a deal.