Browner chose not to appeal the positive test, reportedly for Adderall, and missed the final four games of the regular season.
Browner had 44 tackles, three interceptions and six passes defensed before the suspension. He is in his second season with the Seahawks after getting pulled from the Canadian Football League because he fit the mold of what Carroll wants: big, physical cornerbacks who can play man coverage.
He was voted as a Pro Bowl alternate in his first NFL season, and ended up playing in the game as an injury replacement. Last season Browner had 54 tackles and six interceptions, two of which were returned for touchdowns.
To make room on the roster for Browner, Seattle placed cornerback Walter Thurmond on injured reserve. Thurmond started initially in place of Browner, but suffered a hamstring injury before Seattle's Week 15 game at Buffalo and aggravated the injury last week trying to get back for the season finale.
Seattle, the No. 5 playoff seed in the NFC, visits the Washington Redskins in a wild-card round game Sunday.
Information from The Associated Press was used in this report.