Morley, who turned 38 in May, revealed he will retire at the end of the season.
The front-row forward appeared in the inaugural Super League Grand Final with Leeds Rhinos in 1998, losing against Wigan, but won the Challenge Cup final with them the following year at Wembley.
He also featured with Bradford Bulls in 2005 after joining on a short-term loan deal from Sydney Roosters, helping Brian Noble’s side to defeat Leeds in the Grand Final.
He is the most capped England and Great Britain player of all time and will make what could be his final home appearance for Salford against Sheffield Eagles on Sunday and hang up his boots at the end of the month.
“I’ve been fortunate to have a long career but it’s time to call it a day,” Morley said.
“I’ve been a bit torn and I will miss it, but you’ve got to finish at some point.
“The defining moment came the other week when we played Bradford. I hurt my neck and made my decision then.”
Morley, who will run out to a guard of honour by his team-mates on Sunday, is currently the only active player from the pre-Super League era, having begun his professional career with Leeds in 1995.
He had a successful six-year spell in the NRL with Sydney Roosters before returning to Super League with Warrington in 2007.
He led the Wolves to Challenge Cup final glory at Wembley three times in four years and captained them to a maiden Grand Final at Old Trafford in 2013 before completing a move to his home-town club.
Morley led the Red Devils in 2014 and, although he handed over the captaincy to Harrison Hansen this year, he has maintained a regular place in the team, having missed only six matches in his two seasons at the AJ Bell Stadium.
Morley, dismissed just 12 seconds into Great Britain’s Test match against Australia at Wigan in 2003, made 23 appearances for England and won 30 caps for Great Britain.