The club also announced the termination of contracts for its other two overseas players, South African spinner Keshav Maharaj and West Indies batsman Nicholas Pooran.
Kamlesh Patel was tasked with navigating Yorkshire County Cricket Club through a racism scandal involving British Asian cricketer Azeem Rafiq.
Englishman Paul Farbrace will succeed Graham Ford as Sri Lanka's head coach from the start of next year, the country's cricket board said on Friday.
'I felt isolated, humiliated at times. I lost my career to racism.'
Players security beefed up after lynching incident in Pakistan
Curran went unsold in February's IPL auction but Kolkata Knight Riders recruited him for around $247,000 earlier this month to replace injured Australian paceman Mitchell Starc.