The 20-year-old, who has featured regularly for Newcastle United’s first team during pre-season, has linked up with Jim Bentley’s League Two side and will remain at the Globe Arena for the first half of the 2018/19 campaign.
Former Everton centre half Yarney made his first team bow for the Magpies in the 2-0 pre-season victory over St. Patrick’s Athletic in Ireland last month, before going on to play against Hull City as United prepared for the new season.
He made a total of 30 appearances for Newcastle’s under-23 side last season, scoring twice.