One source told WKNR that Haden tested positive for the prescription drug Adderall, a banned substance in the NFL that is commonly prescribed to treat attention deficit disorder and narcolepsy, during a routine offseason test.
The site is reporting that Haden has been notified of a positive first test and would be suspended if a second test from the original sample shows up positive.
A Browns spokesman declined to comment on the report.
Haden is considered one of the top young cornerbacks in the league. This would be the latest hit to a defense that might be without three starters in the season opener. Outside linebacker Chris Gocong (Achilles) is out for the season, defensive tackle Phil Taylor (pectoral muscle) is expected to be sidelined for at least the first six games and outside linebacker Scott Fujita (suspension) is scheduled to miss the first three games.
The NFL didn't immediately respond to an email from ESPN.com.