Life after Sir Alex Ferguson was never going to be straightforward for United, and so it is proving.
David Moyes' side have endured an indifferent start to the campaign and lie ninth in the table, five points adrift of Saturday's visitors Southampton.
Mauricio Pochettino's side impressed in defeat at Old Trafford last season and are now looking to condemn United to back-to-back home defeats in the league for the first time since 2002.
Saints are on a run of four successive wins in all competitions and, while confident of getting a result in the North West, Davis rejects the notion that United are on the wane.
"For us, I think it is a game to look forward to," he said. "I am sure Man United won't take us lightly after the start we've made.
"These are stadiums you want to play at and players you want to test yourself against.
"I think it is the biggest test. Every Premier League game is a test because you're coming up against top players, but I think coming up against Man United, obviously being champions, is a game we can look forward to.
"The defence has been the platform for our success so far. The last couple of games we've managed to score a couple of goals as well.
"Last year we went up to Old Trafford and came away feeling disappointed not to get a result.
"We played some really good stuff, especially in the second half, and we can take confidence from that and hopefully put in a similar performance and get a better result.
"We can go there, try to play the way we can, and if we do then we are more than capable of getting a result."
Davis will be hoping to retain his starting berth at Old Trafford, just days after the Northern Ireland captain netted for his country.
The 28-year-old's second-half strike in Tel Aviv earned the Green and White Army a 1-1 draw against Israel, helping to restore some pride in the final match of World Cup qualifying
The result ensured Michael O'Neill's men would not finish bottom of Group F and heartened Davis ahead of the Euro 2016 qualifying campaign.
"It has been a frustrating campaign for us," he said.
"We always knew it would be a transitional period in terms of the new manager coming in and younger players coming in.
"They will have taken a lot of experience from the games we've had this year and hopefully it can benefit them.
"Hopefully we can learn from the mistakes we've made in this qualification campaign and take into the Euros and do a lot better."
Davis might not be heading to the World Cup next summer, but he will no doubt be an interested onlooker with several team-mates likely to be involved.
Dani Osvaldo, Maya Yoshida and Rickie Lambert will hope to be heading to Brazil, while Luke Shaw has been mentioned as a potential late call-up.
The 18-year-old left-back has shone for Saints since breaking into the first team last year and has been a key part of what has so far been the Premier League's best defence.
"I wouldn't rule him out, put it like that," Davis said.
"He is a top, top player. He is only 18 years of age and the quality he has got already is unbelievable.
"Hopefully he can keep progressing the way he is and if he does he has a very bright future ahead of him.
"He came in and he looks as if he has been playing at this level for a long time. He looks like a seasoned campaigner.
"There is obviously a lot more in him than what he has shown already.
"He is still only 18 and, if he keeps developing the way we know he can and keeps his feet on the ground, which I am sure he will because he is a level-headed lad, he has a really big future of him."