Aston Villa defender Tyrone Mings has sustained a "significant" knee injury that will require surgery and a "lengthy rehabilitation process".
The 30-year-old England international was carried off on a stretcher during Villa's 5-1 defeat at Newcastle.
Mings has missed just 12 Premier League games since Villa were promoted back to the top flight in 2019.
He has played 155 times in total since joining from Bournemouth in 2018 and has also captained the club.
It is the second serious injury for a Villa player in the space of a week after midfielder Emi Buendia was ruled out for up to eight months with a knee ligament injury sustained in training.