Ruben Amorim has said his Manchester United side are causing him to be "anxious" and "nervous" while the players get to grips with his tactical demands.
Amorim recorded his first victory as United boss with a 3-2 win over Bodo/Glimt in the Europa League on Thursday.
The Norwegian side briefly led 2-1 in the first half and the Portuguese coach has admitted watching his team in the early weeks of his reign is nerve-shredding.
"I get anxious because I don't know what will happen -- you don't control nothing at the moment -- we are trying to see different things," Amorim told TNT Sports.
"I don't know the players and we have not worked a lot together. We go to the game excited, but at the same time you are nervous because you don't know how the game will go."
Amorim made six changes to the team which drew 1-1 with Ipswich in his first game in charge bringing in Lisandro Martínez, Tyrell Malacia, Antony, Manuel Ugarte, Mason Mount and Rasmus Højlund.
The 39-year-old said he saw improvement against Bodo/Glimt but revealed he will be forced into more changes when Everton visit Old Trafford in the Premier League on Sunday.
"I think we have improved from Ipswich and we improved in the quality with the ball," he said.
"We will have to change players [against Everton]. We tried to press all the time and the last 10 minutes it was tough.
"I felt Rasmus Højlund was dead. I felt some players were tired.
"Antony come back from injury, he had to go out of the game and we did four substitutions because of the fitness of the players. We are in that moment and we need the squad together."