Ole Gunnar Solskjaer says Manchester United have to prove they can be consistent if they are to compete with Liverpool and Manchester City for the Premier League title next season.
Solskjaer's side faces a battle for Champions League qualification with United, who have lost six of their past eight games in all competitions, three points behind Chelsea in the race for a top-four finish.
United have not won the Premier League since Alex Ferguson retired in 2013 and Solskjaer is uncertain over how competitive the Red Devils can be in 2019-20.
"I don't think we've got the consistency to do that," Solskjaer told reporters when asked if United can fight City and Liverpool for the title next season.
"Over the last 18 games, we're not far away from them but it's doing it over the course of a season. We've done it for half a season now. Let's see. You can never say never."You cannot expect things to happen overnight and we know that. It will happen gradually and we have to be realistic enough as a club that we have to take it step by step.
"That's not changing 10 players now and bringing 10 players in. It's slowly, slowly but surely. It has to be the right quality, the right personality, the right standards to get us back to where we want to be."
Ahead of a derby clash with rivals City at Old Trafford on Wednesday, United are 24 points behind leaders, Liverpool, although they have played one match fewer.