Manchester United's trip to Brighton on Sunday did not go to plan.
Jose Mourinho's side were expected to emerge victorious in the game, but they were second best throughout on the day as they were defeated 3-2.
Understandably, Man United's defence werecalled into question following the result; particularly the two centre-backs.
It is no secret that Mourinho attempted to bring in defensive reinforcements this summer.
Toby Alderweireld, Harry Maguire and Jerome Boateng were just three names the Portuguese boss had on his shortlist.
But he was unable to seal a deal for any of his targets, meaning he had to make do with the options already at his disposal.
Eric Bailly and Victor Lindelof were the two that were given the nod against Brighton, but they flattered to deceive.
And Gary Neville has now questioned whether they are good enough to be successful at Man United, and has backed Mourinho to switch to three at the back following the result against Brighton.
"What we've seen are two players in Eric Bailly and Victor Lindelof who are lacking confidence a little bit or maybe they aren't quite good enough," he said on the Gary Neville Podcast.
"To me, they look like second-fiddle centre-backs.
"I think it will force Manchester United and Jose Mourinho to go three at the back. I think, with the centre-backs he's got, he will resort to that.
"When I look at the centre-back partnerships that he had at Chelsea, they had power and strength in his teams. He hasn't got that here yet."
That perhaps won't go down well with Man United fans.
Manchester United have always been a team known for their attacking football; a reputation built under Sir Alex Ferguson.
But playing five defenders will go completely against that.
However, it could be a tactical switch Mourinho has to make. His defence was not good enough against Brighton. It's clear something needs changing.
It won't be easy on the eye but it will make Man United more solid at the back.
And that's clearly an area that Mourinho must address at this current time.
Do you think United should switch to five at the back? Have your say by leaving a comment below.
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