Worrall had struggled for game time under new manager Nuno Espirito Santo, and the club have taken advantage of the Turkish window being open longer to finalise a move that could see Worrall move on for good.
Forest were charged with Profitability and Sustainability breaches by the Premier League last month, so it is in their best interest to recoup as much as possible for players currently not getting game time.
Along with fellow defender Scott McKenna, Worrall was banished from the Forest first-team late into Steve Cooper's reign as manager early in December.
No official reason was given as to why, but Worrall spent two months out of the side altogether, before starting against Blackpool in the FA Cup under new manager Nuno.
McKenna had already departed to join Copenhagen, and Worrall has now followed suit, leaving on loan until the end of the season.
Besiktas have the option to make the move permanent in the summer, meaning it is likely Worrall has played his last game for the club.
The 27-year-old has played 226 first-team games for the Garibaldi, including 30 in the Premier League last season as he helped his side to top-flight survival on their return to the division.
However, following the signing of Murillo, and the return from injury of Willy Boly and Moussa Niakhate, Worrall has been unable to play his way back into the side.
After spending the first half of the season on loan at Norwich City, Hwang looks set to follow Worrall to Turkey, with an agreement being reached over a loan move to Alanyaspor.
Fabrizio Romano claims that the deal is done and will run until the end of the season, but there is no option-to-buy included.
Hwang returned to the City Ground after making 18 appearances for the Canaries this season, but he has not featured in a single matchday squad since.
The South Korean is yet to make a single competitive appearance for Forest since joining from Bordeaux in 2022, having spent time out on loan at Olympiacos and FC Seoul, as well as the switch to Norwich.
Despite featuring for the South Korean national side in November's internationals, Hwang was overlooked for a spot in their Asian Cup squad, so he could make his debut as soon as Sunday, when Alanyaspor travel to Fenerbahce.