Barnsley have sacked assistant manager Micky Mellon and goalkeeping coach Ian Willcock.
Manager Danny Wilson, who replaced David Flitcroft in December, is expected to bring in a new number two in a bid to rescue the club's season.
The Reds currently lie bottom of the Sky Bet Championship, three points from safety with 11 games remaining, and have won only three of their 15 league matches since Wilson took charge.
A club statement read: "Barnsley Football Club has (on Wednesday) terminated the employment of assistant manager Micky Mellon and goalkeeping coach Ian Willcock with immediate effect.
"The club would like to place on record its thanks to both Micky and Ian for their service and wish them all the best for the future."
Former Fleetwood boss Mellon, 42, joined the club in December 2012 to assist Flitcroft, who had been placed in temporary charge following the sacking of Keith Hill.
Flitcroft was made permanent manager the following January and the pair kept the club in the Championship by securing a point at Huddersfield on the final day of the season.
Willcock, 35, had worked as goalkeeping coach at Bury, Carlisle, Accrington and Rochdale before joining Barnsley's backroom staff under Hill in December 2011.
Development coach Paul Heckingbottom will continue to assist Wilson, who could opt to bring in the experienced Frank Barlow, with whom he worked at Sheffield United before the pair were dismissed in April 2013.