"Kevin Smith's rehab from a torn ACL is going well, by all accounts. But the Detroit Lions are looking to upgrade at running back as the NFL draft approaches next month.

"I can do almost everything except run," Smith wrote in an upbeat blog posted Wednesday at smith34.com. "I'm not even trying to run right now, though I know I could. It would probably make the knee swell up. I'm lifting weights and doing everything else I can do."

Smith wrote that he thinks he's "right on schedule" but also said "there's no timeline" for the knee. As coach Jim Schwartz said this week at the NFL owners' meetings, "It's not measured in days or weeks. I mean, you're measuring the rehab in months."

The Lions are taking a patient approach with Smith, who went down Dec. 13 at Baltimore. (He also played through two shoulder injuries last year but wrote he is feeling good and won't have surgery.)

"Any time you go through rehabs that are long, you're going to have good days and bad days, and you can't overreact to that," Schwartz said. "You have to sort of look at the whole trend. His trend is up.

"Whether he's ready at the beginning of training camp, whether he's ready during the season, he'll be ready. It's just a matter of when.""