Guildford, 27, is returning to New Zealand after Waratahs signed two-time Australia international Taqele Naiyaravoro.
Despite suffering a broken toe, Guildford – who signed a short-term deal with the New South Wales outfit – made seven appearances.
The 10-time All Black's departure from Waratahs was confirmed on Monday.
Naiyaravoro is back for a second stint in NSW, having made 20 appearances for the team across 2014 and 2015.
Waratahs are sixth in the Australasian Group in Super Rugby and face Sunwolves on Saturday.