Harry Maguire was overheard shouting "Lino, you're allowed to f****** tackle!" after the referee's assistant flagged for a foul against Manchester United.
The Red Devils captain made a nervy start against Newcastle at Old Trafford on Sunday, and was even seen having words with Fred after a mix up in the United box.
This isn't the first time Maguire has been heard shouting at a referee's assistant, after he made his frustration with one known in United's recent 3-3 draw with Everton.
The Red Devils captain was defending United's precarious 3-2 lead over the Toffees when fellow England international Dominic Calvert-Lewin fouled him.
The linesman saw nothing wrong with the challenge, prompting Man United centre-back Maguire to loudly shout: "Are you taking the p***?"
Manchester United go into the match with Newcastle in third, after Leicester City beat Aston Villa earlier on Sunday.
Pep Guardiola's Manchester City, meanwhile, extended their advantage at the top with a 1-0 win over Arsenal at the Emirates.
Victory for United against the Magpies would see them reclaim second spot on goal difference, but they'd still be a staggering 10 points behind champions elect Man City.
