Celtic have agreed to pay Brighton a £2.5million fee to take Shane Duffy on loan for the season, Football Insider can reveal.

The Republic of Ireland international is set to step away from his national team duty today to undergo a medical with the Scottish giants.

Sources at both clubs have told Football Insider that the terms of the deal are agreed after Brighton upped their asking price for the loan fee from £2m to £3m.

Celtic refused to meet the full demand but have upped their initial offer of £1m by £1.5m to get the deal over the finish line.

The Hoops will also cover most of Duffy’s salary of around £45,000-a-week across the season.

Celtic are finalising the deal over the next 24 hours as they look to have the defender’s registration in place well ahead of the restart of their domestic programme.

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Duffy is in line to slot into the Celtic defence for their next match against Ross County on 12 September.

He will be competing with Christopher Jullien, Kristoffer Ajer and Nir Bitton for a starting spot after the international break.

It is likely Neil Lennon will immediately make Duffy a first choice given how hard he has pushed for the deal to be completed.

It comes at a time when there is doubt over the future of Ajer, with five weeks of the transfer window remaining.

The Norway international has fallen out of favour for some matches this season amid speculation of a move to the Premier League or Serie A.

In other news, Celtic have agreed the terms of a blockbuster signing after medical completed.