The Latics return to Wembley for the third time in as many months as FA Cup winners to face last season's champions on Sunday.
Boyce is adamant there has been no time to mourn the loss of top-flight status after eight years as a change of manager - Owen Coyle replacing Roberto Martinez - and the arrival of several new players has brought a renewed confidence.
That was reflected in their 4-0 win over Barnsley on the opening day of the Sky Bet Championship season and they head to the capital in good spirits.
"Because we have so many different players here we haven't had time to think about relegation," said Boyce.
"We know what we need to do. The chairman has told us what he expects and the manager is the same.
"As players we want to get back in the Premier League and the new players would only have come here if they thought the club would go up.
"I don't feel less of a player. We all have our own personal goals to achieve and that is to be back in the Premier League.
"To play against Manchester United so early will show us how far we need to go to put our mark down in the Championship.
"It will be a massive game to show we can compete at that level. There is no real pressure. This is how we are going to test ourselves to see how good we actually are against the champions of England."
In May Boyce lifted the cup after victory over Manchester City and while that may be the most memorable achievement of his career, there has been little time to reflect.
Even since returning from a summer break there has been little reference to their history-making day at Wembley.
The 33-year-old admits he will save those moments to enjoy in his own time.
"I went into HMV the other day and bought the DVD," said the full-back.
"I haven't had time to sit down and think about what happened last season.
"So many new players who have come in didn't play in the FA Cup final so you don't want to talk about it.
"Achievement-wise it is brilliant: I went to Barbados in the summer and everyone was talking about it because it was a major achievement for a club the size of Wigan.
"But everyone at the club is focused on getting back into the Premier League.
"It is going to be a hard campaign but as a player you just want to play and they come thick and fast in the Championship and you have Europe to throw in as well.
"The manager has built a fantastic squad. A lot of people have a point to prove and the manager has assembled a team to get us back into the Premier League, arguably stronger on paper than last year."
Both clubs have had a change of manager and United boss David Moyes will be hoping to win his first trophy after 11 barren years at Everton.
The Red Devils will be expected to sweep aside their lower-placed opponents - as they would even if Wigan were still in the Premier League - and Boyce hopes that plays into the Latics' hands.
"It is going to be his (Moyes') first major game trophy-wise and he obviously wants to go there and make a statement himself, but hopefully we can spoil the party," he said.
"It will take some pressure away from him if he does win it. Wigan are in the Championship so he won't want those sort of giant-killing headlines. It is a one-off game and the way we played against Barnsley, we go there full of confidence.
"We are going there to win. It is a showpiece event but we will take it as serious as it comes. There is no pressure on us, we can go and enjoy the day."