John Duddy has parted company with trainer Don Turner ahead of his next scheduled bout in Boston on 28 June.
The Derryman's manager Eddie McLaughlin confirmed on Friday that the boxer is no longer working with the highly-respected Turner.
"Don Turner has gone," McLaughlin told BBC Sport.
Duddy is now being trained by Miami-based Pat Burns who previously guided Jermaine Taylor to the undisputed world middleweight title.
Burns worked with Taylor for his first 25 professional bouts, including his 2005 win over Bernard Hopkins, but the then world middleweight champion opted to switch to Emanuel Steward in early 2006.
Turner has trained 19 boxers to world titles including Evander Holyfield, Larry Holmes and Mike McCallum.
Boston's Castle Plaza will be the venue for Duddy's bout on 28 June but the opponent for the contest has yet to be finalised.
Duddy's hopes of landing a world title shot against Kelly Pavlik next month were dashed after he struggled to claim victory over Tunisia journeyman Walid Smichet in in February.
One judge scored the middleweight bout a draw while the other two gave the Northern Ireland man a 98-92 verdict.
Duddy picked up cuts to both eyes in the contest at Madison Square Garden which convinced Pavlik's promoter Bob Arum to look for another opponent for the summer title defence.
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