Pearce returned to Sydney from an overseas rehabilitation clinic on Sunday, having been sent there after being filmed apparently simulating a sex act with a dog while under the influence of alcohol on January 26.
The 26-year-old said he was ready to accept whatever punishment was coming his way and that started with the Roosters suspending him from the leadership group.
"After four weeks in an intensive rehabilitation facility, Mitchell's wellbeing remains paramount," Roosters chief executive John Lee said.
"On the basis of medical advice received by the club, and subject to the satisfactory assessment of his continuing rehabilitation, Mitchell will resume training at the club from Monday, March 7."
The Roosters, who face the South Sydney Rabbitohs in their season opener on Sunday, are yet to decide on a possible suspension for Pearce.