Bayer Leverkusen made the most concrete move earlier in the window, offering a loan with an obligation to buy, but Celta rejected the proposal outright, according to Matteo Moretto.
Ajax also had a loan-with-option-to-buy offer turned down before Beşiktaş made a late attempt in the past few hours, only to find Celta similarly unmoved.
Moriba, who plays as a central midfielder, joined Celta permanently in 2025 for a €6 million fee after impressing on loan the previous season, having endured a difficult spell at RB Leipzig following his move from Barcelona.
The Guinea international, who has won 25 caps for his country, is expected to stay in Galicia beyond this summer, with Moretto reporting there is no prospect of an exit before the window closes.
Celta Vigo had themselves negotiated a discount on Moriba's transfer fee from Leipzig, with Barcelona also entitled to 10 per cent of any onward sale as part of the terms attached to his original departure from the Camp Nou academy in 2021.
He signed a four-year contract when the move to Celta was finalised, with a release clause reported at €30 million, underlining the club's determination to secure a player who has become an important figure under head coach Claudio Giráldez.
Moriba's role in Celta's midfield has grown significantly since his loan spell began, contributing to a campaign that ended in European qualification for the Galician club after a long absence from continental competition.
With his versatility and improved end product, the 23-year-old is increasingly viewed as one of the more understated success stories of Spanish football's lower-profile clubs this season, making Celta's refusal to sanction a departure for a fraction of his value unsurprising.
Born in Conakry, Moriba came through Barcelona's academy after moving to Spain as a child, making his first-team debut for the Catalan club before a high-profile switch to Leipzig in 2021 for an initial €16 million plus variables.
That spell in Germany never fully took off, with loan moves to Valencia and Getafe along the way before Celta gave him a fresh platform to rebuild his career. His improved form has also translated to the international stage, where he remains a regular fixture in Guinea's squad.