Is the 24-year-old finally heading to Celtic this summer?
The Daily Mail claimed earlier this month that Duffy - a lifelong Celtic supporter - could be the subject of a £2 million bid from the Scottish Premiership champions, before the trail seemingly went cold for a couple of weeks, inviting other clubs into the reckoning.
Wolves and Swansea City have both been linked, but The Scotsman now report that Bhoys boss Brendan Rodgers could convince Blackburn counterpart Owen Coyle to do business regarding Duffy if he sells Forrest to the Championship club.
The report goes on to suggest that they would be separate deals rather than a straight swap.
Celtic could do with another centre-half. With Charlie Mulgrew yet to be resigned, and Efe Ambrose seemingly heading toward the exit, it leaves Rodgers a bit light on centre-back options ahead of his first season in charge of the Glasgow giant.
Like Rodgers, Duffy is from Northern Ireland but the 24-year-old represented the Republic of Ireland at Euro 2016, where he broke into the side and played in his country's final two games of the competition - and was sent off in their last-16 exit by France.
Forrest, whose contract expires in December according to Rodgers (The Sun), was frozen out of the Celtic set-up by Ronny Deila.