Ritchie was reportedly dismissed by Shepherd yesterday for his refusal to strengthen the squad and Shepherd has wasted little time in bringing in players he wants.
Barnsley and West Brom have agreed a loan deal for Wallwork ahead of tomorrow's deadline and Wallwork is set for talks at Oakwell today.
Meanwhile Brian Howard has spoken out at Ritchie's dismissal.
Speaking to BBC Radio Sheffield, the midfielder signed by Ritchie at the start of last season said:
"I think we could have stayed up. We only needed to tweak a few things, we are still a good group of players.
"It has only gone wrong in the last five games that we haven't competed against the so-called bigger teams."