Dimitri Mascarenhas leaves his post of assistant head coach and bowling lead at Essex at the conclusion of his contract.
Ex-England all-rounder Ravi Bopara signs a one-year contract extension at county side Essex until the end of the 2019 season.
County champions Surrey will start their defence of the title in April 2019 with a home match against Essex.
Essex bowler Simon Harmer signs a contract extension which will keep him at the club until the end of the 2021 campaign.
Audio & Video
The Test Match Special team share their favourite memories from Alastair Cook's remarkable and record-breaking England career.
Alastair Cook talks to Jonathan Agnew about the high and lows of his career before his final Test, which begins against India on Friday.
When Alastair Cook terrorised Australia in the 2010-11 Ashes, it was a peak he would never scale again, writes Tom Fordyce.
Analysis and opinion from the BBC's cricket correspondent.
How to follow cricket on the BBC
BBC Sport brings you live radio commentary from England's Test series against India.
Cricket alerts, newsletters and social media
Get latest scores and headlines sent straight to your phone, sign-up to our newsletter and learn where to find us on online.
How to get into cricket
How to get into cricket - physical exertion with a chess-like element in matches which range from half an hour to five days.