Scott was placed on injured reserve Wednesday, leaving the Raiders minus one of their most productive and versatile players.
The third-year defensive end, who tied for the team lead in sacks each of the last two seasons, was also a key member of Oakland's special teams before suffering a torn ACL while covering a punt against the Steelers.
"I think it's huge," Raiders coach Tom Cable said. "We've been fortunate to not lose too many guys like this. He does do a lot for our football team, playing in base defense as well as third down and [on] a number of special teams. It's a big loss but we're going to have to rally."
Scott's injury left the Raiders in a scramble mode trying to find a replacement.
Second-year player Matt Shaughnessy is expected to replace Scott in Oakland's starting lineup but the Raiders have discussed using outside linebackers Quentin Groves and Bruce Davis there. They also signed free agent Jarvis Moss, who was released by the Denver Broncos last week.
Of the three, Shaughnessy figures to get the most playing time. He is tied with linebacker Kamerion Wimbley for the team lead in sacks with five and has been splitting time with Scott on the right side of Oakland's defensive line all season.
"They're all going to have to play a little more just because of the situation until we can settle on who we feel like can give us some help," Cable said.
Moss was drafted 17th overall in 2007 to be a pass-rusher in Denver's 4-3 defense. His development was slow, however, and the Broncos moved him to outside linebacker when the team went to a 3-4 in 2009. When that failed -- Moss hasn't had a sack since '08 -- Denver gave him his walking papers.
"I'm not the first person that it happened to and I won't be the last," said Moss, who has only five tackles this season. "I'm just going to do what they ask me to do and whatever ends up happening this weekend, that's exactly what I'm going to do. I'm just learning [and] trying to adjust."
The Raiders haven't said how they plan to use Moss or even if he'll suit up for Sunday's game against Miami.
Cable said earlier this week the team might use Groves at defensive end, something he did during two seasons with Jacksonville. The coach reiterated his stance Wednesday but added that the Raiders are also looking at using Davis.
Cable conceded that replacing Scott won't be easy, even though the 26-year-old didn't get his first full sack until last week against Pittsburgh and has only five quarterback hurries this season.
As a team, the Raiders are fourth in the NFL with 29 sacks.
"[Scott's] tempo, his effort to the quarterback has pushed that quarterback to a lot of sacks with the other guys," Cable said. "They've benefited from Trevor's effort, no question."
The Raiders released a statement given by DE Richard Seymour on Monday regarding his ejection from Sunday's loss to Pittsburgh. Seymour apologized for hitting Steelers quarterback Ben Roethlisberger and called his actions unprofessional. He was fined $25,000 by the NFL earlier this week. ... Injured CB Nnamdi Asomugha (ankle sprain) was limited in practice but should be in the lineup against Miami barring a setback.