Ali was initially named in the squad for the final fixtures of England’s Caribbean tour but he will now fly home after the fifth ODI in St Lucia on Saturday.
Ben Stokes and Jos Buttler will do likewise, with the trio granted two weeks off before joining up with their IPL franchises – Stokes and Buttler are in Rajasthan Royals’ squad, while Ali will play for Royal Challengers Bangalore.
Curran will also feature in the upcoming edition of the IPL where he was picked up by the Kings XI Punjab franchise this season.
The Surrey left-armer has played nine Tests and two ODIs for England but is yet to be capped in the shortest format.
England and West Indies are currently locked at 1-1 in the five-match ODI series after the third game was washed out without a ball being bowled.
The T20I series will begin on March 5, with the final game scheduled for March 10, less than two weeks before the IPL commences on March 23.