The Chargers have signed their fifth and seventh-round picks from the 2008 NFL Draft, running back Marcus Thomas and tackle Corey Clark, both to four-year contracts. Thomas, 6-0, 215, rushed for 1,166 yards and 16 touchdowns as a senior at Texas-El Paso. The Chargers selected him in the fifth round with the 166th overall selection. Clark, 6-6, 315, was a two-year starter at Texas A&M. He was taken in the seventh round with the 234th overall pick. The Chargers still have three draft picks unsigned. They include first-round choice Antoine Cason, third-round choice Jacob Hester, and sixth-round choice DeJuan Tribble.