The 43-year-old, who has also managed Lincoln City, spent part of last season on the backroom staff at Glanford Park.
When he left the club at the end of last month it was announced he was seeking a return to management, but will now work under the new Saddlers boss Jimmy Mullen at the Bescot Stadium.
"I'm delighted to have John on board. He's a young guy with a wealth of experience," said Mullen.
"He has experience of youth development and has also held a number of coaching and managerial positions.
"He's a welcome addition to the backroom staff and I'm looking forward to working with him."