Manchester United manager Jose Mourinho says "some [players] care more than others" at the club after their failure to win any of their past three games.
In their last two league matches United have drawn with Wolves and lost to West Ham, slipping to 10th in the Premier League table as a result.
They were also knocked out of the Carabao Cup by Championship side Derby.
Asked if he was worried about his position if the side's poor form continued, Mourinho replied: "No."
Mourinho was speaking before United play Valencia in a Champions League group match on Tuesday.
"Every player is different, no player is the same," he said. "I see different actions but what you see is not really inside.
"I see upset people, some people that don't look like they lost a game.
"I see so-so but in the little two sessions of training we had [since Saturday] everything was normal, desire to work and play."
Mourinho added: "What I can do to improve things I do, and I will improve the things that depend on me and my work."