Shane Duffy's brother has fuelled transfer speculation by posting a Celtic badge on his Instagram page.
The Brighton defender has held talks with the Parkhead club, the team he grew up supporting.
However, Neil Lennon faces competition from Leeds United and West Ham in his pursuit of the Irish international.
On Monday Duffy dropped the latest hint over his future as he posted an picture taken out of an aeroplane window, and now his brother has got in on the act.
Tony Duffy took to Instagram to post an image of the Celtic crest, causing fans to speculate that a move to the Premiership champions is getting closer.
Brighton have returned to pre-season training, with Duffy expected to join up with this team-mates.
However, he is not part of Graham Potter's plans for the 2020-21 campaign.
Celtic are one of his options, with Lennon confirming: "We have made tentative enquiries and we'll see how that goes."
Lennon is in need of a centre-back with just Christopher Jullien, Kris Ajer and midfielder Nir Bitton available.
Duffy has played over 100 games for Brighton, as well as winning 32 caps for his country.
He'll get the chance to add to that after being included in Stephen Kenny's first Republic of Ireland squad for the matches against Bulgaria and Finland.
