Walker worked with Chester when the current Wakefield coach was in charge at KR, and also when Chester was assistant coach with Scotland for a year.
“We tried signing him here,” Chester told Love Rugby League.
“But I understand his reasons for wanting to go to a top four club.
“What a fantastic talent that kid is.
“I think he’s certainly a future Great Britain international, if they bring the team back.”
“There’s a lot of people behind the scenes there doing a lot of hard work,” he said.
“Keith Hogg is still the chairman. It’s taken a long time to get where they are, but what a fantastic result that was.
“Credit has to go to people like Keith, Dave Rotheram and Steve McCormack, who have done a fantastic job in getting the squad they’ve got together.