Schofield was waived by Arizona and Smith was traded by Jacksonville.
Unless the Seahawks get healthy in a hurry, both could be Week 1 starters for Seattle.
"I've got a great coaching staff right here and they've been teaching me a lot of new techniques and a lot of things I've been working on in my game to be able to let it go and turn it loose this weekend and show you guys what I can do," Schofield said.
Just like a year ago, the Seahawks enter the season opener with questions at a specific position group. Last year, they centered on quarterback Russell Wilson making his first NFL start. Wilson is no longer a question, but how many healthy bodies Seattle may have along the defensive line has yet to be determined.
Three important pieces returned to practice Wednesday with defensive tackles Tony McDaniel and Brandon Mebane and defensive end Cliff Avril all getting some practice time. All three were limited, according to the team's injury report. McDaniel and Mebane have groin injuries and Avril has a hamstring injury.
If all three can go, the Seahawks should be fine with depth.
If they can't, Seattle suddenly becomes very thin up front with the chance that Smith, acquired in a trade with Jacksonville last Saturday, would be a starting tackle and Schofield, a converted outside linebacker learning a new position, would be one of the starting ends.
"We will see where Cliff stands. We don't know if he's far enough along," Seattle coach Pete Carroll said. "But we would like to see the tackles play. We think they can."
Seattle had yet another injury issue pop up Wednesday when Brandon Browner injured a hamstring and was limited in practice.
The injury concerns seem to be the only cloud hanging over the Seahawks as they begin a season of huge expectations. It started with the news that Percy Harvin needed hip surgery the only major injury thus far but the nagging problems have piled up.
Avril was first bothered by a sore foot, only to finally get back into the training camp routine and hurt a hamstring. Avril was the marquee defensive free agent move the Seahawks made in the offseason in the hopes of bolstering their pass rush.
He said the injuries have been frustrating.
"As a player you want to get out there as soon as you feel like you can go. But sometimes the training staff doesn't think it's smart to do that," Avril said. "Sometimes you have to battle through some things. Hopefully, we can get everybody back here in the next week or so."
If Avril can't go, Schofield would get his first shot at showing he can make the transition from outside linebacker in a 3-4 defense to defensive end in the Seahawks' hybrid 4-3. Schofield said the biggest difference is that he's almost always going toward the quarterback.
"It's just being stout," Schofield said. "I haven't faced any double teams playing in the league. When you're an (outside linebacker) you're basically outside of everything, but being able to play (defensive end) and being able to set that edge is very important."
McDaniel was another free agent signing by the Seahawks, but he played in only one preseason game. He was a projected starter along with Mebane as the anchors for a run defense that last season held Carolina to 82 yards rushing and 190 total yards in Seattle's 16-12 victory.
Another option for Seattle at defensive tackle could be Michael Bennett. Yet another of Seattle's free agent signings to make over its defensive line, Bennett can play tackle and end.
NOTES: DE Chris Clemons (knee) was on the practice field Wednesday but did not participate as he continues to recover from major knee surgery. Carroll said on Monday that he thought Clemons would be able to practice. ... DT Jordan Hill (biceps) and rookie OT Michael Bowie (shoulder) did not practice. ... Jermaine Kearse will be Seattle's kickoff returner while Golden Tate will get first crack at returning punts.