Maguire joined Liverpool's Academy in 2005 at under nine level. The left-sided defender progressed through the ranks and spent a month on loan at Leyton Orient at the beginning of 2015/16, where his only appearance was in the Football League Trophy.

With Liverpool's squad depleted by injuries, Maguire was on the bench for the third round FA Cup tie at Exeter City on 8 January 2016, coming on as a 77th-minute substitute for the injured Tiago Ilori before returning to his familiar role in the under 21's for the rest of the season. After failing to make any further breakthrough the following season, he joined Fleetwood Town on 13 January 2017 on a two-and-a-half-year deal but made just twelve appearances in eighteen months. After making just one League Cup appearance in the first month of 2018/19 he was loaned to League Two Crawley Town for the rest of the season, making thirty appearances and scoring once, before being released by Fleetwood on the expiration of his contract.