Jamaican defender O'Neil Thompson has left the club after his contract was mutually terminated.
The Kingston-born 27-year-old was signed by former manager Simon Davey in the summer of 2009 from Norweigan outfit Notodden FK but only made the one appearance for the Reds in a year and a half at the club.
He spent time last season on loan with Burton Albion and made two appearances and was set to re-join Davey when the Welshman took over at Darlington. Davey's ill-fated spell of two and a half months caused Thompson to re-direct to Hereford.
Thompson then ended up signing for the Bulls, making six appearances. Davey was then sacked by Hereford at the beginning of October. They have also terminated his loan contract after the Jamaican expressed his desire to return to his homeland.
Bulls caretaker boss Jamie Pitman said:
"O'Neil has been unsettled for some time and we thought it best for everyone if we came to this agreement.
"Everybody at United wishes him the very best for the future."