Manchester United have been changing defenders regularly this season as they handle the demands of the Premier League, EFL Cup and the Europa League. As a result, they've suffered from injuries and costly individual errors.
Jose Mourinho has overseen the club's worst start to a Premier League season and his side have conceded more goals than any of the top six teams in the league so far, letting in 15 from 13 games. With only two clean sheets in the past 10 league matches, there is room for improvement.
Although the attacking side of United's game is also a problem, the Daily Record have reported that Mourinho has been given the green light to strengthen the team's defence in January.