The 31-year-old's decision to relinquish the role came in the wake of a text messaging scandal involving a Knights employee.
After a meeting with club staff, Pearce told the Knights' playing group of his decision on Wednesday before their return to pre-season training on Thursday.
The former NSW State of Origin halfback read a written statement to reporters at a media conference on Thursday, the first time he has spoken publicly since his wedding to fiancée Kristen Scott was called off last month.
