Tandy has Matt Sherratt and Danny Wilson as permanent assistants while Dragons duo Dan Lydiate and Rhys Patchell, like Jones, have returned to Wales duty after helping with defence and kicking, respectively, in the autumn campaign.
Wales will assess whether they need to bring in specialist scrum expertise, although former hooker Wilson has previously coached the set-piece.
Tandy admitted the loss of former loose-head prop Jones, who has coached Ospreys since 2018, is a “distraction” before a tough test at the Allianz Stadium.
“I’m disappointed for Duncan because I know how much it means to him to coach his country and be around the group,” he added.
“He was still in camp on Wednesday and reviewing the scrums, although he couldn’t get down to the field.
“It is a distraction but our feelings are for Duncan because he’s a great character and the players absolutely respect what he does.”
