"Obviously it's been a hard couple of season's performance-wise," said Mannering, who will captain the side for the last time in their final pre-season game against the Dragons in his home town of Nelson on Saturday. "It's not the playing side of it. It's just the extra commitment outside of football that wore me down a bit.
"I definitely didn't achieve what I wanted to as captain and results-wise, but I thought as a player this is probably the best thing for myself and, in turn, hopefully the club."
Initial talks late last year about providing him with leadership support culminated in Mannering asking to be relieved of the role altogether.
Coach Andrew McFadden and managing director Jim Doyle asked Mannering to reconsider but McFadden acknowledged the debilitating effect a miserable end to their 2015 campaign had on Mannering's health and suggested his weariness is a culmination of dealing with several years of off-field change and unrest at the club.
"I saw how much the end of last year was taking a toll on Simon," said McFadden. "It's all the stuff off the field and also what he's had to endure as a captain over the years - the change over of key personnel, key leadership people. He's had to endure all that."
Now he's feeling good about his game. He's fit, healthy and him standing down as captain is only going to take a little bit more pressure off and allow him to play his best footy."
Hoffman, who joined the Warriors from Melbourne last season, insists the change in captaincy will alter little about the way the side functions or how he or Mannering play alongside each other.
"In terms of playing, I don't think anything is going to change," said Hoffman. "It's certainly not going to change what I do on the field. Simon's still a leader at this club. The title has changed but his status with the team and within the leadership group hasn't diminished.
"I've been involved in leadership groups over the last 10 years and I've been lucky enough that my two captains at club level have been Cameron [Smith] and Simon. They're both international captains and at Origin level I've had Danny Buderus and Paul Gallen, so I've had some pretty good mentors."