Republic of Ireland defender Richard Keogh could be out until December of 2020 after injuring himself in a car accident.
The Derby County captain was involved in what the Rams called "an alcohol-related incident" last week, which saw teammates Mason Bennett and Tom Lawrence charged with drink driving.
Scans have revealed that the 33-year old has damaged his anterior cruciate ligament and his medial collateral ligament in the collision.
Keogh is in the final 18-months of his contract at Pride Park and his injury could keep him out for 15 of those.
Derby promised last week that the players involved would "pay a heavy price" for the events that followed a trip bowling and a "scheduled team-building dinner".
A statement last week chastised all involved, "They should have known when to stop and also ignored the opportunity to be driven home using cars laid on by the club, and chose to stay out."
Both Bennett and Lawrence trained with the rest of the Derby squad on Monday, and are in contention to face Barnsley in the SkyBet Championship on Wednesday night.
The club are to investigate the events of last week, but it's understood any punishments forthcoming will only be enforced once legal proceedings have been completed.
Bennett and Lawrence are both due in court on October 15.