Right-back: Trent Alexander-Arnold (Liverpool)
The Liverpool right-back has fallen short of his lofty standards this season, but Trent Alexander-Arnold gets the nod over Aaron Wan-Bissaka. That's because the Manchester United full-back has been inconsistent defensively, leaving plenty of gaps at the back and contributing precious little in the attack as well.
Meanwhile, Trent Alexander-Arnold has come into his own in the last few games, showing signs of his old, rip-roaring self. He will hope to get something against Manchester United, a bogey side he normally struggles against.
Centre-back: Harry Maguire (Manchester United)
Liverpool's misfortune with injuries, especially to centre-backs like Virgil Van Dijk and Joe Gomez, who've missed almost the entirety of the season, leaves the door ajar for Harry Maguire, who has featured consistently for Manchester United this season.
Although Maguire is yet to fully justify his high price tag, the former Leicester City man has considerably improved in his second season at Old Trafford. He has helped Manchester United maintain good defensive form and could be key to keeping out the likes of Mohamed Salah and Diogo Jota.
Centre-back: Ozan Kabak (Liverpool)
Harry Maguire may have been consistent for Manchester United, but the same cannot be said of his defensive partner, Victor Lindelof. The Swede has looked suspect in defence many times and has been erratic too. That explains why Ozan Kabak gets the nod here. The young Turk arrived in January and has brought about a semblance of normalcy to Liverpool's chaotic backline.
Kabak's start to life at Liverpool was shaky, and he seemed to lack confidence, but he has settled in seamlessly since then, proving himself to be a useful presence during his team's ongoing defensive crisis. Nevertheless, the 21-year old will face his toughest examination yet on Sunday when he goes up against a free-scoring Manchester United team.
Left-back: Luke Shaw (Manchester United)
Under normal circumstances, Andrew Robertson would've walked into this combined XI. But Luke Shaw has been in a league of his own this season, enjoying his best season with Manchester United to date.
The Englishman has usurped Alex Telles to make the left-back spot his own, producing brilliant performances during the campaign. He's almost guaranteed of a starting berth at the upcoming Euros for England.