Manningham is dealing with a right shoulder injury, and with Kyle Williams already out for the season with a knee injury, Matt Maiocco of CSN Bay Area reports Sunday should finally see the debut of the 49ers 2012 first-round draft pick.
The 49ers drafted Jenkins out of Illinois with the 30th overall pick, but the rookie has suited up for only two games this season. But with Michael Crabtree, Randy Moss and Ted Ginn as the only other healthy wide receivers, coach Jim Harbaugh says Jenkins has earned the time to be out on the field.
"I've seen progress from A.J.," 49ers coach Jim Harbaugh said. "He's been on his assignments. He's executed well when he's been out there. He's giving great effort, and football rewards effort."
If Manningham is able to play, Jenkins will probably get bumped from active duty again. Manningham is second on the 49ers in receptions with 41 catches for 449 yards and one touchdown.