Starters Julian Peterson, Derek Smith and Jeff Ulbrich are locks to make the roster, as is Jamie Winborn, the team's second-round draft pick this year. Stewart, rookie Shane Elam and veteran Terry Killens are the only other linebackers still with the team. The Niners appear certain to keep at least six linebackers.
That leaves Stewart tantalizingly close to his dream of making the team as a rookie. It could come down to how well he performs Friday night in the Mile High City.
"This has a lot more weight to it than previous games," Stewart said. "This is where they are really evaluating, to see who can make this team and be an asset to this team. I have high expectations this game and expect big things from myself."
Stewart is eighth on the team with seven preseason tackles, which ranks him third among linebackers behind Ulbrich and Peterson, who lead the team with 12 each. In the final minutes of San Francisco's second exhibition game, Stewart put a crunching hit on Oakland running back Jabari Jackson that forced a game-clinching fumble in a 20-17 win that stands as the Niners' lone victory of the preseason.
Stewart also has made his presence known on special teams, and that ultimately may be the deciding factor on him making the team.
"That's the big thing for me. That's where you make the team," Stewart said. "They're looking for a special teams guy, a guy who can go down and make plays, make something happen. That could be the key."
After Friday's game, the Niners must trim their roster from 65 players to the regular-season limit of 53 by 1 p.m. Sunday. That will make for a long Saturday for youngsters such as Stewart.
"The heart's going to be pumping," Stewart said. "So, you know, I'll just be waiting and anticipating what is going to happen."