The Patriots on Thursday placed offensive lineman Jamey Richard (concussion) on injured reserve and claimed rookie guard Dustin Waldron off waivers from the Dolphins, the team announced.
In addition, offensive lineman Nick McDonald passed his physical and was removed from the active/physically unable to perform list, according to a source. McDonald had missed the first seven practices of training camp, including Thursday afternoon's session, with an undisclosed ailment.
Richard suffered a concussion in Sunday's practice. The former Colts lineman had signed with the team in May.
Waldron (6-foot-5, 305 pounds), was waived by the Dolphins this week after signing as an undrafted free agent in April. He is the second Dolphins castoff offensive lineman the Patriots signed on Thursday, joining tackle Derek Dennis.
He is scheduled to arrive in town Friday morning, taking a red-eye flight from Eugene, Oregon.