David de Gea 7/10 – Put in his usual match-saving performance with a couple of superb stops at either end of the second-half to keep United in contention for the three points.
Paddy McNair 5/10 – A nervous start saw Van Gaal opted to take him off six minutes before the break after a series of poor errors. There will be better times ahead but this was somewhat of a wake-up call.
Chris Smalling 5/10 – Lasted just 18 minutes before a clash with Dusan Tadic forced him off with a suspected calf muscle tear. Just doesn’t seem to be able to catch a break fitness-wise.
Marcos Rojo 5/10 – Still looks suspect in defence but that’s perhaps not surprising considering the chaos around him. That said, his World Cup form seems to have deserted him.
Antonio Valencia 5/10 – Just doesn’t look comfortable as a wing-back, as Sadio Mane gave him a torrid time. Couldn’t even get forward due to Southampton’s territorial dominance.
Michael Carrick 6.5/10 – A calm and reliable presence in midfield, before dropping into defence after McNair went off. He looked just as assured there, too. A big asset to Van Gaal since his return.
Marouane Fellaini 4/10 – After his recent resurgence, last season’s Fellaini returned with a vengeance on the night. Gifted the ball to Southampton for Graziano Pelle's 31st-minute equaliser and continued to prove careless in possession.
Ashley Young 5.5/10 – Has taken to a wing-back role better than Valencia but failed to make a big impact on this occasion, despite working hard throughout the 90 minutes.
Juan Mata 5/10 – One of those nights where he just couldn’t get into the game whatsoever. Needs to start proving his £37.1 million price tag if he wants to shake the persistent exit rumours.
Wayne Rooney 5.5/10 – Was poor on the ball for most of the night but delivered when it matted with a pin-point free-kick to find Van Persie at the back post for the 71st-minute winner.
Robin van Persie 7/10 – Starved of service up top but was rewarded for keeping alert with two clinical finishes. As long as he can remain fit, then the Van Persie of old might just re-emerge.
Johnny Evans (Smalling 18) 6/10 – One of United’s better defenders in his first-team return but there were a few obvious moments of rustiness. Nevertheless, having the Northern Irishman back will be a big boost moving forward.
Ander Herrera (McNair 39) 5.5/10 – Came on for the struggling McNair but spent most of his time chasing the ball.
Darren Fletcher (Mata 89) N/A