The Frenchman was dropped from the Hoops starting line-up for the Europea League qualifier first leg against Jablonec on Thursday after failing to hit the net in the opening three games of the season.
And according to reports in France, the 23-year-old has entered talks with the Seagulls over a possible transfer move ahead of their English top flight opener away to Burnley next Saturday.
A fee in the region of £15m has been mooted for the wantaway star, who is now in the final year of his contract after scoring 82 goals across four campaigns at Celtic Park.
After turning down approaches in the past, the Glasgow side are now ready to cash in on a player they signed from PSG for in a club record fee of £9m in 2017.