On 23 December, Basel announced that they were loaning [[Jonathan Dubasin]] out to [[Real Oviedo]], in the second highest Spanish league, until the end of the season and the loan-contract had a purchase option. They also said that the loan move was primarily due tofor personal reasons. During his time with FCB early in the season, Dubasin was out for a long time on with a ligament injury in his foot. By the winter break he had made eleven appearances in all competitions (ten league, one cup), in which he scored three goals and made one assist.<ref name="fcb-aktuell-FCB-Dubasin loan-Oviedo">{{cite web | first = | last = FC Basel 1893 | author-link = | date = 23 December 2023 | url = https://www.fcb.ch/aktuell/news/1-mannschaft/transfer-dubasin/ | title = Jonathan Dubasin wechselt leihweise zu Real Oviedo | format = | work = | publisher = FC Basel 1893 AG | language = de-ch | trans-title = Jonathan Dubasin on loan to Real Oviedo | access-date = 2023-12-23}}</ref> On 26 December 2023, the club announced that they had signed [[Benjamin Kololli]] on a free transfer and that he had signed a two-and-a-half-year contract, which contained an option for another year.<ref name="fcb-aktuell-2023/24-FCB-Kololli">{{cite web | first = | last = FC Basel 1893 | author-link = | date = 26 December 2023 | url = https://www.fcb.ch/aktuell/news/1-mannschaft/transfer-benjamin-kololli/ | title = Benjamin Kololli wechselt ablösefrei ans Rheinknie | format = | work = | publisher = FC Basel 1893 AG | language = de-ch | trans-title = Benjamin Kololli is moving to the Rhine knee on a free transfer | access-date = 2023-12-26}}</ref> On 5 January, the club announced that they had signed [[Nicolas Vouilloz (footballer)|Nicolas Vouilloz]] from [[Servette FC|Servette]] on a four-and-half-year contract, dated up until sommer 2028.<ref name="fcb-aktuell-2023/24-Servette-Vouilloz-FCB">{{cite web | first = | last = FC Basel 1893 | author-link = | date = 5 January 2024 | url = https://www.fcb.ch/aktuell/news/1-mannschaft/transfer-nicolas-vouilloz/ | title = Nicolas Vouilloz wechselt zum FCB | format = | work = | publisher = FC Basel 1893 AG | language = de-ch | trans-title = Nicolas Vouilloz moves to FCB | access-date = 2023-11-16}}</ref>