SANTA CLARA — An excited Colin Kaepernick traced his optimism for the 49ers’ coming season to a “cleaned-up” offense.

Specifically, Kaepernick credited the streamlined approach to new coordinator Geep Chryst and his replacement as quarterbacks coach, Steve Logan.

“We’ve cleaned a lot of things up, and made it more comfortable and friendly for players to be able to go out and make plays,” Kaepernick said at Tuesday’s start of a mandatory minicamp.

Among the friendly sights are the new deep threats in Torrey Smith and Jerome Simpson. Kaepernick completed a couple of passes to Smith over 20 yards in the afternoon team drills inside Levi’s Stadium, where the 49ers plan to practice more in hopes of better familiarity with the home field.

Kaepernick believes his more compact throwing motion will enhance his deep-ball accuracy, which he’s happy to test out on Smith and Simpson, among others.

“They bring a lot of speed to the field, a lot of deep, vertical threat,” Kaepernick said. “That’s something I’m looking forward to this coming season, having the opportunity to take (deep) shots.”

The 49ers offense ranked 30th in passing and 20th in total yards last season, in the final year under coach Jim Harbaugh and coordinator Greg Roman. Their 19.1 points per game ranked 25th.

Kaepernick said he does not feel he’s under more pressure, however, merely because the defense has lost six potential starters.

“I do feel like I need to do more, but not because of that,” Kaepernick said. “Offensively, last year for us, we feel it was a letdown. We should be able to do more, and we plan to do more this year. We’re working toward that.

“As far as our defense, they’re confident with who they have and who’s playing. They’re confident in their abilities to make plays over there.”

To improve the 49ers’ confidence at home, first-year coach Jim Tomsula will hold some minicamp practices inside Levi’s Stadium, as well as some training-camp sessions in August. The 49ers went 4-4 in their inaugural season at the $1.3 billion venue.

“It’s always good to be as comfortable as possible with your home field,” Kaepernick said.

Added Tomsula: “We’d like this stadium to feel like something old to us.”

Tomsula didn’t stress a need for Kaepernick to become more of a vocal leader in the wake of losing past captains Frank Gore, Justin Smith and Patrick Willis. “Just for the record, where Colin is at right now, who he is and what he’s doing, I’m his No. 1 fan,” Tomsula said.

Aldon Smith sat out the second half of practice after having a toe stepped on in team drills. Smith did not seem overly concerned, nor were team trainers, who initially wrapped his right foot in ice and drove him on a cart to the sideline, where he watched the remainder of practice. Smith gave general manager Trent Baalke a thumbs-up as he got carted off the Levi’s Stadium field, and they joked with each other toward the end of practice, after Smith walked gingerly on the foot.