HITC Sport understands League One club are closing in on a deal for forward.
Clark currently finds himself on the fringes of the first-team at Ibrox and a number of Scottish Premiership and Championship clubs have shown an interest in landing him this month.
Can they get him?
The 24-year-old's current deal is due to expire at the end of the season and although Rangers are still considering an offer, a move during this window is looking increasingly likely.
The son of former Rangers ace Sandy, Clark joined the Gers in 2013 from Queen of the South and meant his career had come full circle as he was released by the club when he was just 14.
Now Clark looks set for a move away from the club and League One Barnsley are confident of pulling of something of a transfer coup by persuading him to make the move to Oakwell.