The ex-Celtic and Hibs defender replaces his former Easter Road team-mate Chris Hogg following the latter’s departure to become assistant boss at MK Dons last week. His appointment has been described as “short-term” by the club.
Caldwell came through Newcastle’s youth ranks between 1997 and 2001 before leaving for Hibs.
The former Scottish international with 55 caps has previous experience in management with Wigan Athletic, Chesterfield and Partick Thistle.
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