Former Manchester United captain Roy Keane has come to the defence of Paul Pogba, insisting both Romelu Lukaku and Alexis Sanchez should be doing more to lift the side out of their current slump.

United laboured to a goalless draw away to Sevilla in the first leg of their Champions League last 16 clash with the La Liga outfit on Wednesday (21 February) – with Pogba again starting the match from the substitutes' bench.

But with Ander Herrera forced off after just 17 minutes, the France international was brought on ahead of schedule. Despite the introduction of the their record signing, United offered little at the Ramon Sanchez Pizjuan Stadium, with an extraordinary save from David de Gea to deny Luis Muriel saving them from falling behind just before half-time.

Sanchez and Lukaku, who combined to help see United through to the quarter-finals of the FA Cup against Huddersfield Town last Saturday, both endured underwhelming evenings in the final third, with the Belgium international spurning United's best chance when he volleyed over the bar from close range.

Pogba has born the brunt of the criticism aimed at United during a difficult period for the club where they have won just two of their last five games. But former skipper Keane believes the club's problems stretch beyond the former Juventus midfielder.

"Pogba is a really good player," Keane said during his appearance on ITV's Champions League Highlights show. "He is under a lot of pressure at the moment, there is a lot of speculation about him, he was left out tonight – but you still have to have him in your starting XI.

"Off the field, he has a big personality – social media, his haircuts, the cars he drives, he needs to bring that to the pitch. But United's problems aren't just with Pogba. Lukaku needs to do more, Sanchez has got to do better, they need to reinvest in some defenders."