Sir Alex Ferguson has reportedly threatened to drop Wayne Rooney in the future if the striker fails to perform in training.
The England international was fined by the Red Devils along with teammates Darron Gibson and Jonny Evans following a night out on Boxing Day.
The 26-year-old was then excluded from the Premier League champions' 3-2 defeat to Blackburn Rovers on Saturday due to under-performing in the side's recent training session.
It is believed that Ferguson has warned Rooney that if he doesn't step up in training, he faces the chop from the 70-year-old's starting lineup, according to The Mirror.
Despite the recent controversy, the frontman is expected to return to the club's starting XI against Newcaste United tomorrow.