Stafford wasn't much more forthcoming himself as the Lions returned to practice Tuesday after their bye week.
The rookie quarterback has missed the last two games with a knee injury, and with backup Daunte Culpepper (hamstring) also at less than 100 percent, Schwartz is going to make the St. Louis Rams try to prepare for Stafford, Culpepper and third-stringer Drew Stanton.
"Absolutely nothing," said Schwartz, when asked what he would reveal about Stafford's participation in Tuesday's practice. "I do think the bye came at a good time for getting people healthier, and everyone was able to at least do something, but that's as far as I will go."
Stafford took part in the individual drills that are open to the media, but acknowledged that he wasn't fully involved in the full-team portion of the session.
"I was limited," he said. "I didn't get all the reps, but I took a few. This is the most I've done on it, and it felt pretty good."
Stafford, though, knows that he's been down this road before. The last time he tried to go through most of a practice, the knee swelled and he had to have a second MRI.
Stafford's biggest target, Calvin Johnson, is also recovering from a knee injury. He was limited to playing catch on the sidelines with a Lions staffer during the early portion of practice.
"I did exactly as much as coach said I did," Johnson said. "I feel a lot better than I did a week ago, so I'm definitely optimistic, but I'm not positive. I'll see what I can do tomorrow."
Schwartz was equally close-mouthed about the left guard position, which was being manned by longtime tackle Jon Jansen in early drills Tuesday. Daniel Loper and Manny Ramirez have split time at the position in Detroit's first six games.
"I've never played anything but tackle in an NFL game, but I've practiced all over the line," said Jansen, an 11-year veteran. "I'm anxious to take any opportunity I can to get on the field."
The move puts Jansen next to left tackle Jeff Backus, his college teammate at Michigan.
"It's great playing next to Jeff, because I know him so well and we've worked together," Jansen said.
The pair played together until Jansen finished his college career in 1998.
"I'm excited to be out there next to Jon," Backus said. "The last time we played on an offensive line was 10 or 11 years ago at Michigan. I know what kind of player he was then, and I know he wants to show people that he can still be that type of player now."