Could O'Neill help Sunderland to sign the following Watford, Kilmarnock and Hearts players if he gets the job?
Brendan Rodgers missed out on the chance to manage Craig Cathcart at Watford - but could he bring the defender to Celtic?
Reports claim the Watford defender is wanted by Fulham, but he could be ideal for Leeds United instead.
It is claimed that Cathcart is not in Marco Silva's long-term plans at Watford, whose former boss wants him at Fulham.
Manchester United head to Vicarage Road this weekend to face Watford. The Hornet's will have an ex-United man in their ranks, so here is a look back at six players who spent time at both clubs.
Cathcart was part of Watford's successful Premier League survival bid last season, and he is keen to silence the critics once again.
Craig Cathcart has suggested that Northern Ireland boss Michael O'Neill could handle a job in the Premier League, comparing him to Watford's Quique Flores.
Arsenal defeated Watford 3-0 at Vicarage Road in the Premier League on Saturday.
Leeds United, Cardiff City, Rotherham United, Watford and Derby County stars are among the best defenders in the Championship this weekend.