Middlesex's head coach, Richard Scott, has left his role with the county, who are mid-table in Division Two of the County Championship and failed to qualify for the knockouts in the Royal London Cup.
Richard Johnson, the assistant coach, will take on Scott's role for the remainder of the Championship campaign. Daniel Vettori is already in position to be coach for T20 Blast, which starts this week, although since winning the T20 title in 2008 they have underwhelmed in that format.
Scott took the head coach position in 2009 and guided Middlesex to promotion in 2011 before they won the Championship on a thrilling final day of the 2016 season when Toby Roland-Jones (who has been ruled out for this season with a back injury) claimed a hat-trick.
The following summer, however, they were relegated and their attempts for an immediate return to Division One have not been convincing this season with two wins in seven matches. In their most recent match against Kent they were bowled out for 56 and 124.
"On behalf of Middlesex Cricket I would like to thank Richard for all that he has given the club as head coach during the past 10 years; he has been a loyal, hard-working, committed and high quality coach," Angus Fraser, Middlesex's managing director of cricket, said.
"As with every coach in professional sport we have shared highs and lows but to play a leading role in a side winning the County Championship is a triumph very few coaches can claim. Under his guidance more than a dozen cricketers have gone on to gain international recognition.
"A process to recruit a new head coach for 2019 will commence immediately."