In their first season of competing following promotion from the Championship, United cruised to a ninth-place Premier League finish last season.
Marcelo Bielsa’s side stunned opponents with their oppressive, all-attacking style, and quieted suggestions they would tire by winning all of their last four games of the season.
The Whites have not thrived in the same way this season as, with three wins from 18 games, Leeds are in 16th place and five points above the relegation zone, where Burnley have been stuck since August.
Ahead of Sunday’s game, the Clarets boss implied that Leeds set themselves unsustainable standards in their first term in the top flight.
“They had such a flying season last season and they set the bar very high with the way they played, their performance levels,” Dyche said.
“It is not easy to do that season on season in the Premier League.
“I think they probably knew and were realistic that there is a challenge, that it might be a tougher season.
"They’ve got more points than us currently and they’ve managed to get wins on the table.
“They're a decent outfit, but they're maybe not purring as much as they were last season."
With three points at stake on Sunday for two teams fighting the drop, Dyche insisted that it will be business as usual for his team.
"The games around you are considered more important but you get three points if you win, no extra,” Dyche said.
“We’ll be working hard every game, as we did last night [against Manchester United], and see where that takes us.
"The last year has been a challenge for many people, not just in football.
“But we’re in the Premier League, we’ve earned the right to be there, we deserve to be there and we’re looking to stay there."