Former England Under-21s manager Pearce, who spent 12 years with Forest as a player, was thought to be keen on taking over from Billy Davies, who was sacked by the club earlier this week.
But Pearce, 51, who was caretaker manager at the City Ground during the 1996-97 season and went on to manage Manchester City, has decided the job is not for him at this time.
"We understand there were discussions between Pearce and John McGovern, who is the new adviser to chairman Fawaz Al Hasawi, about the manager's position," Dorsett explained.
"It would have been a sensational return to his former club but Pearce has decided it is not the right job for him at this time and he will not become their new manager."
The east midlands club are believed to be casting their net wide and have also been linked with Malky Mackay, Steve Clarke, Roberto Di Matteo and Gianfranco Zola amongst others.
But Dorsett reports Forest have hit stumbling blocks with all these names and Mackay is also likely to be ruled out of the running along with Pearce and Neil Warnock, who also turned down the job this week.
"There has been contact between Mackay and the club but any deal would be complicated because of the terms of his departure from Cardiff," Dorsett said.
"Mackay has an impending court case with Cardiff owner Vincent Tan and he is unlikely to take over as a result of that.
"Forest have been frustrated with some other targets too because of issues with gardening leave. Clarke has been contacted but he is on gardening leave with West Brom, which makes things difficult, and likewise with Di Matteo.
"Zola, I am told, may not be interested in the job until the summer. He would like the job full-time but Forest would like to make a temporary appointment and then review things again at the end of the season."