Millwall manager Neil Harris has confirmed that 18-year-old midfielder Daniel Kelly will join the club on January 1, following a pre-contract agreement after his contract with Celtic expires. Despite interest from clubs like Bayer Leverkusen and Tottenham, Kelly chose Millwall as he had been excluded from Celtic's first team under Brendan Rodgers, who was unable to secure a new deal with him. Harris expressed excitement about Kelly's potential, comparing him to a young George Saville and highlighting his box-to-box playing style and passion for the game. Kelly had turned down a reported £5,000-a-week contract with Celtic, opting to play in the Lowland League for the remainder of the year. Celtic is reportedly seeking around £500,000 plus sell-on bonuses for Kelly, significantly more than the £275,000 Millwall offered for an earlier transfer. This move reflects Millwall's strategy to evolve by integrating younger players into their squad.