21-year-old, Louis, who once worked at the Doncaster Rovers club as a hospitality waiter, has been issued with the number 28 shirt for the 2013/14 season.
He has signed as a non-contract player in aid of Bluebell Wood Children's Hospice in Sheffield.
More top news
European Union leaders are attending a special summit later to formally agree their Brexit negotiating strategy.
Most places across the UK will stay dry all day, with sunny spells, particularly in the south.
The Royal Marine jailed for killing an injured Taliban fighter in Afghanistan has spoken for the first time since being released from jail.