Manchester United's hierarchy is planning a significant defensive overhaul for next summer, acknowledging a poor start to the season and insufficient investment in the backline. Lisandro Martinez is reportedly considering leaving, with Atletico Madrid and other Spanish clubs showing interest in the Argentine defender. His contract expires next year, but United can trigger an extension. Luke Shaw's future is uncertain, as an extension hinges on him accepting a substantial wage cut from his £200,000-a-week salary. Conversely, Harry Maguire is expected to stay, with the club set to trigger his contract extension. United is targeting Newcastle's Lewis Hall and Bournemouth's Adrien Truffert for full-back positions. The club also intends to sign at least one central defender, with Matthijs De Ligt's fitness being a key factor. Youngsters Ayden Heaven and Leny Yoro are being developed. January market activity is not ruled out if results continue to decline.