Winston, who was elected NFL Players Association president earlier this year, played last season for the Arizona Cardinals. The 30-year-old Winston is entering his ninth NFL season after debuting in 2006 with the Houston Texans.
The offensive line is considered one of the weakest position groups on the team, so Winston could add stability there. The defending Super Bowl champions are dealing with running back Marshawn Lynch's holdout over a contract dispute. Seattle signed former Giants cornerback Terrell Thomas on Monday.
- Paul Palladino