Updated

New York, NY (SportsNetwork.com) - Washington Redskins tight end Fred Davis was suspended indefinitely, without pay, by the National Football League on Wednesday for an unspecified violation of the league's substance abuse policy.

The ban takes effect immediately.

"I would like to clarify the circumstances that resulted in my current suspension. In the past, I made the mistake of knowingly ingesting a banned substance. For over two years, I've worked very hard to eliminate marijuana from my life, and I have not had a positive test for it since 2011," Davis admitted in an NFLPA-issued statement released shortly after the ruling.

"Unfortunately, a couple of months ago I took a supplement that contained a banned substance. I now know that supplements are not regulated by the FDA and may contain banned substances. The NFL Policy is strict, and not knowing that a supplement might contain a banned substance doesn't excuse a violation of the policy.

"I've worked closely with the NFLPA and NFL to resolve this violation, and I will be permitted to apply for reinstatement in the fall. I look forward to staying in football shape, remaining in compliance with the NFL policy, and having a chance to get back on the field to contribute to a team's success next season."

Davis posted seven catches for 70 yards and one touchdown in 10 games for Washington last season.