Celtic have accepted an offer from Norwich City for goalkeeper David Marshall.
The Championship club have negotiated a fee, thought to be close to £1m, with Celtic chief executive Peter Lawwell.
"If Celtic manager Gordon Strachan gives the go-ahead, David will have a medical on Monday or Tuesday," Willie McKay told BBC Sport.
"He just wants to play regularly and, with Peter Grant, Jim Duffy and Bryan Gunn there, he won't be homesick."