Bruno Fernandes could barely contain his shock as Manchester United suffered a nightmare opening to their Carabao Cup second-round encounter at Grimsby.

The Red Devils skipper was named among the substitutes, with Ruben Amorim choosing to hand Kobbie Mainoo a starting berth.

However, the Premier League heavyweights faced embarrassment in the opening period, falling behind 2-0 to their League Two hosts.

Charles Vernam broke the deadlock first, finding the net to put the home side ahead.

Fernandes appeared devastated by his team's defensive lapse, with television footage capturing him burying his face in his palms.

Matters deteriorated further when Tyrell Warren capitalised on an error from Andre Onana - who had been handed a rare opportunity between the posts amid doubts surrounding his future - to slot home after just half an hour.

Boss Amorim finds himself facing mounting scrutiny following a torrid beginning to his tenure at Old Trafford.

He has managed to collect merely 28 points across 29 league matches since taking over from Erik ten Hag last November.

United invested £200million in revamping their attacking options during the summer transfer window, yet have started the 2025-26 season poorly by securing just one point from their first two outings.

The Red Devils concluded the previous campaign in 15th position - their most disappointing Premier League showing - and club legend Wayne Rooney recently declared that Amorim has "no excuses" for the current struggles and may soon find himself battling to preserve his position.

"There are no excuses now for the manager this season," the 39 year old said on his BBC podcast, The Wayne Rooney Show.

"He's got to start getting results and getting results quickly because once you start getting into October, November, if results don't change drastically then that's when pressure comes.

"United really needed to hit the ground running this season and one point from six is a worry. It's only two games into the season but the worrying sign is we're seeing things that we saw last season and that's a concern."

Benjamin Sesko, Matheus Cunha and Bryan Mbeumo were snapped up in costly transfers to bolster United's forward line.

However, the 20-time English champions, who suffered defeat to Tottenham in May's Europa League final, were defeated 1-0 at home by Arsenal on the opening weekend before squandering a spot-kick and throwing away their advantage in Sunday's 1-1 stalemate at Fulham.

When questioned whether Amorim is the correct choice for the future, Rooney responded: "It's difficult to sit here and say, 'yeah 100 per cent' - I don't think anyone could do that.

"I don't think Ruben would probably say that himself with what we've seen since he's been at the club.

"I think the recruitment has been good in the summer - I still want to see two or three more players brought in.

"But it's difficult (to say), 'right, this is going to be our manager for the next five years' on what we've seen."