Winston, drafted in third round by Houston in 2006, has started every game for the Texans in each of the past five seasons.
Leinart appeared in two games this past season after starter Matt Schaub suffered a season-ending injury in November. The former Heisman Trophy winner completed 10-of-13 passes for 57 yards in a Week 12 start against Jacksonville but suffered a fracture in his throwing shoulder during the game -- his last of the season.
Drafted 10th overall by Arizona in 2006, Leinart spent the first four seasons of his career with the Cardinals before signing with Houston prior to the 2010 campaign. He has thrown for 3,950 yards with 15 touchdowns and 20 interceptions in his career.
Vickers appeared in 14 games with the Texans last season after spending the first five years of his career with the Browns. He has rushed for 87 yards on 34 carries over that span.