Reed, in a Wednesday night radio interview with 105.7 The Fan, admitted the injury may be negatively affecting his play.
But Reed downplayed the injury after practice Thursday.
"(The injury) is not anything to worry about -- I'm not a pitcher," he said. "I can still tackle. ... I don't play baseball. As long as I'm not throwing, it is what it is. I've been dealing with it. It's all right."
Reed, who isn't listed on the Ravens' injury report, didn't specify which shoulder is injured, or when the injury occurred.
The former NFL Defensive Player of the Year said Thursday that he doesn't know why his name was not on the initial injury report.
"I'm sure a lot of guys in this league have had injuries and they're not reported," Reed said. "That's part of the game that fans and y'all don't know nothing about. We have to deal with workman comp situations."
Reed has 24 tackles and two interceptions in six games this season.
ESPN.com's Jamison Hensley contributed to this report.