Context: The Chargers opened the season on September 11, 2006, with a 27-0 victory over the division rival Oakland Raiders. This second game of a Monday Night Football doubleheader marked the first time the Chargers had shutout the Raiders since a 44-0 win in 1961. LaDainian Tomlinson led the Chargers with 31 carries for 131 yards, while Philip Rivers, in his debut as an NFL starting quarterback, completed 8 of 11 pass attempts for 108 yards with one touchdown pass and no interceptions. The Chargers' defense stifled the Raiders' running game, holding Raiders RB Lamont Jordan to 20 yards on 10 carries, and recorded 9 quarterback sacks against Raiders QBs Aaron Brooks and Andrew Walter. Three of those sacks belonged to second-year LB Shawne Merriman. With the win, the Chargers extended their winning streak against Oakland to six games, while head coach Marty Schottenheimer improved his head coaching record against the Raiders to 26-7. Schottenheimer also earned his 187th career victory, passing Chuck Knox to become the seventh-winning-est head coach in NFL history. That shutout also marked the second time ever that Oakland had been shut out in their own stadium, the second being the Denver Broncos and the third being the St. Louis Rams as the Chargers picked up their 6th straight win over the Raiders and started their season 1-0.

Question: how many years had merriman played?

Answer:
2