Niners coach Jim Harbaugh called Dorsey's conditioning "really good" and said the team would increase his workload as the week progressed.
Dorsey originally sustained the injury Aug. 1. It was initially reported Dorsey would miss the entire 2014 season, but Harbaugh said later in August that he expected Dorsey to return late in the year.
Dorsey was placed on the injured deserve/designated for return list after his injury and is first eligible to return for the 49ers' Nov. 9 game against the New Orleans Saints.
With Dorsey's return to practice, San Francisco now has 21 days before it has to activate him or shut him down for the rest of the season.
A first-round pick out of LSU in 2008, Dorsey, 29, had 30 tackles and two sacks with the 49ers last season after spending the previous five seasons with the Kansas City Chiefs. He signed a two-year extension with the 49ers in August worth a reported $6.1 million.
Ian Williams, who was signed by the 49ers as an undrafted free agent in 2011, has filled in for Dorsey in his absence.
San Francisco running back back Marcus Lattimore is expected to begin practicing Wednesday. He has been out since tearing three ligaments in his knee in October 2012 while playing college football for South Carolina.
San Francisco dropped to 4-3 after the loss to the Broncos and is now tied for second in the NFC West.
- Ben Estes