The side have been in brilliant form, losing one game since their loss to Fenerbahce in the Europa League on November 3 and remain undefeated in the Premier League, a run of 16 matches.
While it won’t be easy, Untied have the quality to go into the game and come out with the trophy, as they look to pick up some early silverware and boost the confidence of players at Old Trafford.
Speaking about the situation, Neville isn’t predicting an easy ride for United at Wembley on Sunday.
“I think they will do enough to win the game, but I do not think it will be easy at all,” he said.
“I think Southampton will be well prepared and some of their lads will be playing in the biggest game of their lives.
“And they will play it like that, so United will have to be at their very best.
“He [Mourinho] is a trophy hunter and United are not going to win the league this season, so it looks like the cups are going to be the only way they can win a trophy now.
“And I think it is important for the confidence of the players and where they want to get to eventually, which is Champions League and Premier League titles, that this will be an important stepping stone.
“But yes they have to win, that should be the mentality going into the game.”
Even with Henrikh Mkhitaryan out injured, United have plenty of options and should be winning tomorrow as they challenge for silverware on four fronts.
It’ll be a brilliant game at Wembley, and with excellent memories their from the last year, where the players have won the FA Cup and Community Shield, they’ll be buzzing to get back in action.