The duo joined the Tykes last summer, Gallimore from Town and Handyside from Stoke.
Neither found much success in Yorkshire. Gallimore's infamous moment came during the 0-0 draw against Town back in October - missing a last minute penalty.
Handyside struggled to make a first team place his own and was described as lacking pace by many Barnsley fans.
Handyside will no doubt be linked with a move back to Blundell Park as he is almost every summer now.