The 49ers received an injection of talent on the practice field this week that included a 1,000-yard receiver and a pass-rusher who amassed 19.5 sacks last season.

All-Pro outside linebacker Aldon Smith is back with the 49ers after missing five games while seeking treatment for substance abuse.

“Of course, I didn’t want to be away from the sport I love,” said Smith, who appeared at ease Tuesday while answering questions in front of his locker. “But it was good for me to get away and get my mind together and work to get into the positive spot I need to be at.”

Wide receiver Michael Crabtree also returned to practice after sustaining a torn right Achilles tendon on May 21. While Smith is expected to be available to play Sunday against the Carolina Panthers, Crabtree might require more practice time to get into game shape.

Smith declined to reveal where he sought treatment, saying only it was “out of state.” He entered the facility on Sept. 23 -- three days after his arrest on DUI charges and one day after the controversial decision for him to suit up and play against the Indianapolis Colts. He said he got back to the Bay Area on Oct. 28.

“It’s been a process since I left, you know being back now, it’s been a process,” Smith said. “I’m getting there. Every day is just a step closer to getting to where I want to be.”

When asked where he wants to be, Smith answered, “Maximize my potential. I have a lot of things I can do, and a lot of goals I want to reach. So taking those steps to get to where I want to be is a goal of mine.”

Smith was activated last week off the reserve/non-football illness list. The NFL granted the 49ers a one-week roster exemption, which expires Wednesday.

Smith said he was able to watch some games, keep in contact with some teammates and coaches work out a couple days a week to remain in good physical condition.

Teammate Ahmad Brooks said Smith appears to be a good shape after defensive coordinator Vic Fangio paced the defensive players through an on-field workout.

“I kind of got winded, and I’ve been here all season,” Brooks said. “Aldon wasn’t huffing and puffing, even though he’s gained a few pounds.”

Smith said his focus has been narrow since rejoining his teammates.

“That’s crossing my mind,” he said of Sunday’s game against Cam Newton and the Panthers. “I’m taking it one day at a time, getting back here and being around the guys. Just getting my life back at home. I have a 10 month old son, so I’m doing the father thing. Make sure I’m all ready to go.

There seems to be little doubt that Smith will be ready to play every snap – if that’s how the 49ers decide to use him.

“He’s a freak of nature, so I think he’d be ready to go no matter what,” 49ers defensive lineman Justin Smith said. “But he definitely looks ready to go.”