The Red Sox have scheduled a pair of press conferences for Wednesday to welcome Lackey and Cameron to Boston. Cameron will be introduced at 11:30 a.m. ET and Lackey at 1:30 p.m. ET.
The deal with Lackey, the top pitcher on the free-agent market after spending eight seasons with the Angels, is worth $82.5 million over five years, sources told ESPN The Magazine's Buster Olney.
The acquisition of the 31-year-old right-hander gives the Red Sox one of the best rotations in baseball. He is 102-71 with a 3.81 ERA in 234 career games.
Cameron, who turns 37 next month, batted .250 with 24 homers and 70 RBIs last season for Milwaukee. A three-time Gold Glove winner in center field, he could switch to left with Boston as a replacement for free agent Jason Bay.
Cameron received a two-year contract that would be for a total of about $15.5 million, a source told ESPN.com's Jerry Crasnick.
Information from The Associated Press contributed to this report.