Stafford returned to practice Wednesday after missing Sunday's loss to Pittsburgh with a knee injury. It's not clear whether he has a shot at playing against Green Bay (2-2) this weekend.
"It was good to be doing something again," he said. "The question will be how it reacts tomorrow. I'm not even thinking about playing on Sunday right now -- I just want to see how it feels on Thursday."
Stafford, who injured the knee in an Oct. 4 loss at Chicago, acknowledged that he isn't 100 percent.
"It is on its way, but I can still feel it a little bit," he said. "It's not a lot of fun watching from the sidelines, but we'll have to see how this goes. I'm not going to know for a few more days."
Lions coach Jim Schwartz was cautiously optimistic.
"He's improving -- doing a little more every day -- but there's still a long way to go until Sunday and definitely a lot of ground left to be covered," he said.
Wide receiver Calvin Johnson (knee) did not practice.
"He's also improving, but you saw that he wasn't able to do things today," Schwartz said. "If he can't go, we have other guys who will have to step up, but it definitely changes the way a defense will play us. Calvin is the kind of guy that a coordinator always has to account for when he's on the field."
After the road trip to play the Packers, the Lions (1-4) have a bye week.