Johnstone, 33, has two sacks and his effectiveness has diminished week by week. The former Viking was inactive during last week's 23-14 loss to Houston and went to injured reserve to make room for the Raiders to claim Doug Gabriel off waivers. Johnstone said minor surgery has been recommended on his knee.
"I've been playing with it all year, but after 11 games it's starting to add up. It's swelling and the fact that I've got a broken left toe means I've got problems on both sides," Johnstone said. "I tried to compensate because of the toe and it's affected my knee."
Kevin Huntley, a first-year defensive end out of Kansas State, played well as the nickel end against the Texans with half a sack and some nice pressure on David Carr.
"They told me that with Lance having these nagging injuries, that I should get my mind right and be ready to play," Huntley said. "I think I did OK. There are things I can improve on."