Nübel, 29, joined Bayern in 2020 but never established himself as Manuel Neuer's successor. He spent time on loan at Monaco and then three years at VfB Stuttgart, but returned to find no place in a squad that already holds Neuer, Jonas Urbig and Sven Ulreich. With no room in the goalkeeping department, Nübel has been told his future lies elsewhere.
Beşiktaş are reported to be firmly interested in the goalkeeper, who is currently with Germany at the World Cup. The Turkish club are eager to finalise a deal before their Europa League fixtures against FC Midtjylland in July, adding urgency to negotiations that must satisfy both clubs and the player.
Nübel's camp has acknowledged the situation and the Turkish club's determination to secure the deal.
"We will make the right decision about Alexander's future," his representatives said. "What we can confirm is that Beşiktaş is determined to sign him."
Nübel's contract with Bayern runs until the summer of 2029, meaning any deal would require a transfer fee. Bayern Munich are understood to want the situation resolved before the squad returns, having made clear to the player that there is no path to first-team football at the Allianz Arena.
For Nübel, the decision to move to Turkey is not straightforward. He is a full Germany international and has aspirations to play at the highest European level, making Beşiktaş a challenging sell despite the club's ambitions in European competition. Whether his camp will accept the move or hold out for another option will determine how quickly this situation reaches a resolution.
Bayern, for their part, appear to have made a definitive decision. The club's three senior goalkeepers leave no room for Nübel, and with a pre-season start date already communicated to him, the timeline is clear. Any club looking to sign him will need to move quickly.