The Japan international proved to be a standout player for Brighton last term, registering 10 goals and eight assists in 41 competitive appearances.
While Mitoma has struggled to find his best form at times this season, he has still managed to score three goals and provide six assists in 25 matches this season.
Despite having a contract until June 2027, Mitoma has emerged as a potential transfer target for a number of top Premier League clubs.
According to Football Transfers, Man City, Man United and Chelsea have been given a boost in their pursuit of the Brighton attacker.
Brighton recently confirmed that they had reached an agreement to sign the 19-year-old when the transfer window opens in the summer.
Osman, who will join for a reported £16m fee, will sign a long-term contract with Brighton until the summer of 2029.
With Osman set to strengthen Brighton's wide options, the door could now be open for Mitoma to complete a move away from the South coast ahead of the 2024-25 season.
Although the Seagulls could be open to Mitoma's departure, they are still expected to ask for a significant fee in the region of €60m (£51.2m).
However, the signing of Osman has seemingly dented Barcelona's hopes of winning the race to secure Mitoma's signature.
Fati has scored four goals and provided one assist in 19 appearances for the Seagulls, but he has seen his time with the club hampered by a calf injury, which kept him out for over two months.
With Osman set to link up with his new club in the summer, Brighton may now be reluctant to pursue a permanent move for Fati. body check tags ::