Martin O’Neill admits Celtic made a major transfer window mistake and they’ll have to rectify it in January

Celtic manager Martin O'Neill has admitted the club made a major transfer mistake by failing to replace midfielder Arne Engels before the summer window closed. Engels was sold to West Ham United for £22 million in August, leaving Celtic short of running power in midfield. O'Neill indicated that the club will look to rectify this issue by signing a replacement during the January transfer window.

Since Engels' departure, Celtic have suffered a series of defeats, including a 5-1 Champions League loss to LASK, a 3-0 Premier Sports Cup defeat against Rangers, and a 3-1 Europa League loss to Ferencvaros. Despite spending £31 million on ten new players during the summer, the squad has struggled to replicate Engels' physical presence in midfield.