Essex captain Tom Westley has apologised after alcohol was poured over a Muslim player as the team celebrated their Bob Willis Trophy win.
Batsman Feroze Khushi, who was 12th man during the final against Somerset, was photographed recoiling as beer was poured over him on the balcony at Lord's.
His club admitted the celebrations failed to meet their inclusive values and pledged to do more.
A club statement on Monday read: "The club has worked extremely hard and will continue to bring cricket to anybody and everybody, and educate on diversity, but further work needs to be done across both sport and society in general, to widen people's knowledge and make them more aware of cultural differences."
And Westley added on Tuesday: "On behalf of myself and the team, we would like to apologise for any offence that was caused during our celebrations at Lord's on Sunday.
"At Essex, we believe we have built a strong dressing-room culture that supports one another both on and off the field.
"As a group, we have come together today and discussed the event and on reflection, we are disappointed that we let this happen.
"Moving forward, the squad will be more responsible and aware of our actions and will continue to learn and develop with the help of the ECB and the PCA."
Essex reasserted their status as English cricket's red-ball standard bearers by claiming the inaugural Bob Willis Trophy after a five-day draw was settled on first-innings runs.
The Chelmsford side are the reigning county champions, having also taken the honour in 2017, and now have a third red-ball title in four years.
Although 21-year-old Khushi did not feature in the final, he made four appearances during the group stage.