Gray, now 31, is also wanted by Crystal Palace and Bristol City but a move to Oakwell would be far closer to home.

Harrogate-born Gray started his career at Leeds United 14 years ago and has subsequently played for nine different clubs including Sheffield United, Bradford City and Burnley. Cash-strapped Charlton are willing to off-load after being relegated to League One.

Barnsley manager Simon Davey, meanwhile, is also running the rule over four triallists.

Striker Dean Morgan, goalkeeper David Preece, and defenders Chris Ramsay and Maxime Chanot are training with Barnsley this week in a bid to secure permanent deals.

Morgan, 25, has been released by Luton Town as a result of the club's relegation from the Football League while former Aberdeen goalkeeper Preece, 32, has spent the last three seasons in Danish football playing for Silkeborg IF and OB Odense.

Ramsay, 19, is a Northern Ireland Under-20 international who can play centre-back or right-back and was released this summer by Manchester City.

French defender Maxime Chanot is also 19 and was released by Sheffield United this summer after failing to break into the first-team squad. He played seven games on loan at Mansfield Town last season and was sent off twice.