Captain Marc Roberts and battling midfielder Josh Scowen have both left Barnsley FC for Championship rivals.
Central defender Roberts has joined Birmingham City for an undisclosed fee and has signed a five-year contract with Harry Redknapp's side.
Midfielder Scowen, meanwhile, chose to turn down a new deal at Oakwell and has signed a three-year deal with QPR on a free transfer.
A replacement for Roberts has already been secured with Forest Green Rovers' defender Ethan Pinnock joining on Friday for an undisclosed amount.
Pinnock is capable of playing in the centre of defence and also left-back. He joins Stevie Mallan, Jason McCarthy, Cameron McGeehan and Liam Lindsay as Paul Heckingbottom's summer signings.
