Ole Gunnar Solskjaer says players cannot "fake" their way into the Manchester United side as "you only deserve to be in a team that you contribute to".
A challenging year that started with fan discontent about the direction of the club ended with the Old Trafford giants sat second in the Premier League, just three points behind leaders Liverpool.
United have won seven of their last nine top-flight matches and talk of a title challenge is increasing due to the clear improvements in mentality and squad depth.
Solskjaer has so far been coy on talk about a push for the Premier League crown but was more forthcoming when it came to the great strides taken in his two years in the dugout.
Asked if he senses something has changed in the players and that they are stronger mentally as individuals, the United boss said: "Yeah, definitely.
"One, they're two years older than when I came. Two, some of them are really strong personalities that we've brought in, they've really been a good influence.
"And I think we have competition for places, which means you cannot go around and think that you can just fake your way to being part of this team because you only deserve to be in a team that you contributed (to).
"I think everyone's just realised that we're privileged to be part of Man United, such a fantastic club with a fantastic history.
"When you're here, enjoy it as much as you can and maybe you'll experience some fantastic times.
"You've got winners like Juan Mata and Nemanja Matic. They don't play every single game but they're so influential in the group and in the build-up to games and during games when they're not playing."
Solskjaer made six changes for the last-gasp 1-0 win against Wolves on Tuesday, when Luke Shaw, Anthony Martial and Scott McTominay came off a bench that included the likes of Mata, Fred and Donny van de Beek.
"We have a strong squad, we've rotated a lot," the Norwegian said.
"We've not really called it a settled XI because I don't think this season is going to be about that anyway. It's going to be about the squad. It's going to be about the 25, 26 players.
"I think towards the end of the season that will help us.
"It has to be done this way. When you leave Scott and Fred out, it's not easy because they deserve to play every game. But Nemanja and Paul (Pogba) played so well against Everton so we wanted that midfield.
"Injuries and suspensions will happen, so I think our squad is well capable of being ready for every game."
Solskjaer knows a thing or two about being in and out of the side at United.
Sir Alex Ferguson used to plan teams in advance and sometimes that frustrated players, such as when the Norwegian scored four goals against Everton in 1999 only to then be benched in their next match
"It's horses for courses," Solskjaer said. "Some players you feel are more suitable for some teams but, of course, you do plan ahead.
"I remember those four goals and I remember also the times that you feel you deserve to play and you're left out. That's part of being at Man United.
"You have top players everywhere and we know that throughout the season if you're going to win something you have to contribute.
"Like (against Wolves), Anthony came on and did really well for half an hour. Luke came on and did really well.
"That's just the way it's going to be. Players will have to be angry with me until the next time they play because, believe you me, they're not happy when I tell them they're starting on the bench."
The New Year's Day selection will be interesting against Aston Villa, who are fifth and just four points behind United thanks to the "fantastic job" that Solskjaer believes counterpart Dean Smith is doing.
Solskjaer highlighted their 7-2 win against Liverpool as the result of the season and knows Jack Grealish, who has admirers at Old Trafford, will be tough to shackle.
"He's a player for Aston Villa and England who has only improved," the United boss said.
"I don't want to say too much about other teams' players but of course he's a player we know we have to look for.
"The goal he scored last season (at Old Trafford) was a brilliant goal and we've faced him enough times to know it's going to be a difficult game."
