34-year old Shearer who only just signed last summer from Rotherham United has left the club after reaching a mutual agreement with the Railwaymen.
Shearer who joined the club last season from Championship side Rotherham United and was earmarked to challenge Ben Garratt for the number one jersey.
He started the season playing in the 2-1 defeat away to Fleetwood and the 2-1 home defeat to Barnsley before being dropped. He went on to make his last appearance for the Railwaymen in the 3-0 defeat to Rochdale in the JPT.
Shearer joined Burton Albion on loan in January to gain some game time but only made a sub appearance for the Brewers in the 3-2 win over Cambridge.
So the next stop for Shearer is League Two outfit Mansfield Town who signed the Glaswegian on a free transfer.