Smith, the 2005 No. 1 overall draft pick out of Utah, has been sharp this week, connecting with a handful of different receivers on deep balls while making good decisions in the pocket. All along, he has been the front-runner to begin the season as the starter in Harbaugh's first season as coach.
"It felt better the last few days, kind of getting back in the groove of things, throwing it well, just seeing things well," Smith said. "Still a lot ahead of me, but, yeah, I feel I've put a few days together that are pretty decent."
While he didn't rule out signing veteran Daunte Culpepper to be a third quarterback, Harbaugh said Tuesday that the 49ers would give some other players a look before any decision is made.
"We're looking. But no differently than we're looking at the waiver wire every day," Harbaugh said. "The right guy, if it's the right fit for our situation here. We worked a guy out (Monday) and had a good workout. We'll evaluate some other guys and see what the best fit for us is. ... A third quarterback is something we'd like to have. I think if you don't you're rolling the dice a little bit."
NFL Network insider Jason La Canfora cited a league source in reporting Monday night that if Culpepper signs with the 49ers, it's unlikely to come until next week.
Meanwhile, Smith is still treating it like the 49ers' quarterback job is open, but he knows it's his gig to lose.
Smith was slightly behind after missing the initial six practices of training camp per the new labor rules for when free agents could start workouts.
"I've been so dug in, I really haven't (noticed separation from Kaepernick)," Smith said. "I've just been focused on me and playing better, stringing together some good plays and good practices. I feel like I've done that."
"I feel great about how the offense is set up," said Smith, who threw for 2,370 yards and 14 touchdowns in 11 games last season. "We're together. Everybody's on the same page. There's really one voice."
Kaepernick understands his role for now: the franchise's quarterback of the future waiting his turn.
"Right now, he's the veteran. I'm just buying my time trying to get better and work into that spot," said Kaepernick, a second-round draft pick out of Nevada. "He has seven years of experience, so you expect him to have a little more knowledge of defenses and checks, things like that than a rookie coming in. Right now, I'm just trying to get up to speed and make sure I know all those things so I can really make this a competition."
The Associated Press contributed to this report.