Kelly, who joined the Bangladesh national team in April last year on a two-year contract, resigned before completing his term.
He decided to spend more time with his family and officially notified the board via email at 1 PM on Monday.
During the Asia Cup, Kelly had taken paternity leave. After becoming a father on September 24, he did not rejoin the national team.
As a result, Bangladesh played the Afghanistan series in the UAE and the home series against the West Indies without him. During his absence, Ifthekar Rahman has been serving as the acting fitness trainer for the national side.
Kelly introduced several innovations in the team’s fitness assessment system. Alongside the traditional beep and yo-yo tests, he implemented a new “time trial” fitness test.
Kelly’s fitness programs were widely praised for their structure and effectiveness. Before joining the BCB, the Australian trainer had worked with New South Wales cricket and a professional rugby team as a strength and conditioning coach.