Sunderland are believed to have made initial contact with Martin O'Neill over the possibility of becoming their new manager.
Mark Hughes had overtaken O'Neill as the bookies' favourite to replace Steve Bruce, but it is understood that the Black Cats have made their move to speak with O'Neill.
Bruce was sacked following a poor run of form in the Premier League which has left the Black Cats just two points above the drop zone.
Assistant manager Eric Black has taken temporary charge of the team ahead of Saturday's clash with Wolves.