They believe Said El Mala will remain on board going into the new Bundesliga campaign, despite “one or two offers”.
The Seagulls have been intermittently mentioned in relation to the 19-year-old, as have Brentford.
1FC Koln's sporting director Thomas Kessler said: "There have been one or two offers, which have also become public, but they haven't led to a transfer, and therefore I am firmly convinced that he will play for FC this season."
El Mala is under contract until 2030 although it is thought an offer of at least £45 million might tempt the Cologne club to let him go this summer.
Kessler said: "He's here, he has a long-term contract, and I'm incredibly happy he's here.”
The interview took place on the first day of pre-season training and Kessler said El Mala was "full of energy."
Albion have several wingers on their books, including two who shone on loan in the EFL last season in Amario Cozier-Duberry and Ibrahim Osman.
But it is not clear how many are ready to play prominent Premier League roles apart from Yankuba Minteh and Kaoru Mitoma, who is likely to miss the start of the campaign due to a hamstring injury.