Sean Dyche has credited Ole Gunnar Solskjaer with lifting the mood at Old Trafford and allowing Manchester United to play with freedom.
United were enduring a turbulent campaign under Jose Mourinho, who was sacked in December. The Red Devils have subsequently won eight consecutive games in all competitions since Solskjaer arrived on an interim basis.
Burnley are United's next opponents and Clarets boss Dyche is wary of facing a rejuvenated outfit on Tuesday, having been impressed by Solskjaer's impact.
"From the outside looking in, it seems like he has just tried to loosen a little bit and put more freedom on it," Dyche told a news conference ahead of the trip to Old Trafford.
"A bit more energy seems to have come back to the players. I think that's a skill in itself. I think possibly that is what he has done; he has just given a different feel to the group in his own way.
"But I think they have responded and they are delivering good performances. It seems there is a little bit more spark - not massive tactical changes, but just that spark within the group.
"I am not questioning Jose Mourinho, I think he is an absolutely incredible and top manager. [Solskjaer] has just changed that feeling in the group, coming in, and they have responded."
Burnley are short of defensive options heading into the midweek clash, but the future of forward Sam Vokes was the subject of discussion ahead of the transfer deadline.
Vokes has been linked with Stoke City and Dyche said of the Wales international's situation: "Who knows? I would expect [he will stay] but we are a business, not just a football club. Both have to be in balance.
"We have had varying signs before with people interested in our players and it doesn't surprise me that people are interested in our players, that is just the way it is. We look outside and they look at us. That's just the market."
