But McKinnie didn't make it to the end of the 2½-hour workout, which took place under sunny skies at the team's training complex.
"He worked very hard," coach John Harbaugh said. "He's carrying a little too much weight right now. So, with this heat out there, it made it tough for him to finish."
The 6-foot-8, 360-pound McKinnie was held out of Thursday's session by Harbaugh, who said the left tackle was "in good shape" but too heavy to practice.
After dropping a few pounds -- though neither McKinnie or the Ravens said how many -- he rejoined the first-team Friday and lasted just over an hour before watching the remainder of the session from the sideline.
"I know he's been working hard to get some of the weight off, so he's not eating as much maybe as he would normally," Harbaugh said. "But he's got to tough it out, and he's going to have to perform through that and get in the kind of shape we need him in and that he wants to be in."
After practice, McKinnie entered the training complex from a side entrance that enabled him to avoid the media.
McKinnie was a key figure in Baltimore's run to the Super Bowl last season. He started all four playoff games and helped protect quarterback Joe Flacco, who was not intercepted during the postseason.
The Ravens did not immediately give him an offer as a free agent. McKinnie visited other teams but ended up agreeing to a two-year, $7 million contract with Baltimore in May.