Cameron, 32, was placed on the disabled list with a strained left oblique on April 1 and missed San Diego's first 17 games.
Cameron batted fifth in Sunday's game against the Mets. He hadn't played in a regular-season game since Aug. 11, when he collided with then-Mets teammate and center fielder Carlos Beltran while pursuing a ball in right-center at Petco Park. The collision fractured Cameron's eye sockets and other facial bones.
"Cameron has been cleared to go so we are not going to be cautious with him," Padres manager Bruce Bochy said. "He is good to go."
Cameron batted a career-high .273 with 12 home runs and 39 RBI in 76 games with the Mets last season.
Adkins, 28, is 0-1 with a 10.13 ERA in three games for the Padres.