Coach Jim Schwartz says the No. 1 overall pick in the 2009 draft was to have undergone the surgery after the season. But Stafford was placed on injured reserve Wednesday after a physical exam indicated he wouldn't be ready to play in the Jan. 3 season finale against Chicago.
"We anticipate a minor surgery just to clean out some irritants and debris," Schwartz said. "Since he's had [the injury], he's had on and off swelling. It's been stuff he's been able to play through, but it's also something we knew we needed to address after the season."
Third-year quarterback Drew Stanton will make his first NFL start Sunday against the 49ers in San Francisco.
Stafford injured his non-throwing left shoulder while leading a fourth-quarter comeback that lifted Detroit to a 38-37 victory over Cleveland on Nov. 22. He aggravated the injury in a Dec. 6 loss at Cincinnati, but Schwartz said Stafford's recovery is "on course" and he won't undergo surgery on the shoulder.
Stafford completed 201 of 377 passes (53.3 percent) for 2,267 yards and 13 touchdowns, a record for a Lions rookie. He threw five of them against Cleveland, tying both a team record and the 72-year-old NFL record. He also set an NFL rookie record with 422 yards passing in that game.
Stafford either threw or ran for a touchdown in all 10 of his starts, including one pass in Detroit's 19-14 win over Washington in Week 3. That victory ended the Lions' 19-game losing streak, the NFL's second longest.