While with West Of Scotland Guy played as a part-time pro in the Glasgow district's European Cup team. He played as a contracted player for Glasgow in a couple of spells, interupting his career to concentrate on his medical studies.
He moved from Glasgow to Edinburgh Rugby for the start of season 2002/2003 but is returning west to play for Hawks, and pursue his medical career.
Hawks spokesman Hugh Barrow said: "Guy will be a huge asset to us in our title defence. He has made it clear that his medical activities are his priority and we are happy to accommodate that."