OWINGS MILLS, Md. -- Baltimore Ravens coach John Harbaugh declined to give an exact timetable on Joe Flacco's return, although he has been encouraged by his starting quarterback's progress from a back injury.

"All indications from Joe and our trainer Mark Smith have been very positive," Harbaugh said after Wednesday's practice.

When training camp started on Thursday, doctors told Flacco and the Ravens that the 32-year-old would need about a week of rest to let the back issue subside. It is believed the injury won't linger all season if Flacco takes care of it now.

On Tuesday, Harbaugh told ESPN's Dianna Russini that Flacco is still not in danger of missing the start of the regular season.

"Oh yeah, he's going to be here long before the end of the preseason, I can say that with confidence," Harbaugh said. "Now, if I get proven wrong on that, backs are unpredictable, I guess. But I'm not counting on that. I'm counting on him being back soon."

Flacco, who had never missed a training camp practice before, said he's not dealing with a disk issue. He described it as "a little bit of stiffness" last week.

"It is so early on in camp that it is kind of useless to push through and maybe hurt yourself even more," Flacco said Friday. "That is the thing: We have a little bit of time at this point, and we can take our time a little bit with it. It is not that I want to, but we can, and that is why we are doing it."

The Ravens open the preseason Aug. 10 against the Washington Redskins.