The move brings an end to a spell in Mestalla that never quite delivered on its early promise.
Trabzonspor beat Germany's Schalke 04 to the signing after the newly-promoted Bundesliga side had been closing in on a loan-with-option-to-buy deal in recent days. Valencia's preference for a permanent sale, to raise funds and free up wage space, ultimately tipped the balance towards the Turkish offer. Reported fees have varied between €1.5m and €2m.
Özkacar, 25, came through Altay's academy before Lyon signed him in 2020. Valencia took him on loan in 2022, then made the move permanent for €5m in 2023 on a contract through June 2028. He never established himself as a regular starter, though, and went out on loan first to Valladolid and then to Köln, where he made 27 appearances last season. Cologne opted against triggering their purchase option, sending him back to a Valencia squad he was already expected to leave; head coach Carlos Corberán left him out of the pre-season trip to Girona to help speed the exit along.
The Özkacar sale comes as Valencia captain José Luis Gayá delivers a rallying message ahead of the new season, insisting the squad's unity will matter as much as its football.
"As the standard of football keeps getting higher, whoever is more of a group, more of a team, is often the one who wins matches," Gayá said, crediting Guido Rodríguez's second-half impact last season and describing him as good as a new signing this summer.
"He counts as a signing, of course, even though we already had him in the second half of last season — he helped us a lot. He gave us a lot of hierarchy and leadership in midfield."
The captain also pointed to Mestalla as key to Valencia's ambitions, with two home games — against Betis and Celta Vigo — arriving early in the campaign after Betis were granted a fixture postponement linked to Giovani Lo Celso's involvement in the World Cup final with Argentina.
"I have real ambition to win a lot more matches at Mestalla, which is our temple, our home," Gayá said. "We have to feel very strong there. When we've had great seasons we had that constant bond with the fans, and that's what we need again."