Nottinghamshire have released Phil Jaques from the second year of his contract to allow the former Australia batsmen to become assistant coach with New South Wales Blues.
Jaques, who joined Notts this season, will assist head coach Trevor Bayliss and also look after emerging talent.
The 35-year-old has scored 894 runs in 11 four-day matches, helping the club go second in Division One.
"Phil's made a big impact this season," said director of cricket Mick Newell.
"We would never stand in the way of a player in his situation when a job comes along that's a perfect fit.
"He has performed very well in a position that has been problematic for us in recent times and he deserves a lot of credit for the position we find ourselves in at the moment."