Law, who was appointed by Middlesex earlier in September, finished his stint with the Windies after a disappointing India tour. The former Australian cricketer had joined the Windies in 2017.
Pothas, previously the fielding coach, is expected to bring continuity to the side for the tour of Bangladesh. The appointment is likely to be made full-time post the Bangladesh series.
"Having Nic lead the team at this juncture is important for continuity and we look forward to strong and positive performances from the squad under his leadership," director of cricket Jimmy Adams said.
Pothas said, "It is an honour to be asked to be the head coach of the West Indies Cricket team for the immediate future. The Bangladesh series will be a tough challenge which we look forward to embracing."
The first Test against Bangladesh will be played in Chittagong beginning November 22.
First Published: November 20, 2018, 11:40 AM IST