London - Derby condemned an "alcohol-related incident" that has ruled captain Richard Keogh out of action until the end of the season because of a serious knee injury.
Rams duo Tom Lawrence and Mason Bennett were also charged with drink-driving after a car crash shortly before midnight on Tuesday.
The Championship side revealed Keogh was among those who continued drinking after a team-building dinner with staff on Tuesday evening.
"As a club, we cannot, and do not, condone the actions of a small group of players on Tuesday evening," Derby said in a statement.
"The players were out as part of a scheduled team-building dinner with staff and while the majority of them acted responsibly and left at around 8:00 pm and were not involved, a small group, including the team captain Richard Keogh, continued drinking into the night.
"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.
"As a result of an alcohol-related incident, Richard Keogh has sustained a serious knee injury that will prevent him from playing until the end of the season."
The club said the players involved would face internal disciplinary action and be expected to do work in the community as part of their punishment.
Former Netherlands and Barcelona midfielder Phillip Cocu has had a torrid start to his reign in charge after taking over from Frank Lampard in July.
Derby have won just one of Cocu's first eight league games in charge and are languishing in 18th spot in the Championship, already seven points off a play-off place.