SANTA CLARA — LaMichael James expects to return punts and kickoffs and do whatever else the 49ers might want from him in Sunday’s exhibition, four weeks after dislocating his right elbow in practice.

He’ll reluctantly follow doctors’ orders and face the San Diego Chargers with an elbow brace. “The elbow’s good, it’s stronger and I’m getting more comfortable wearing a brace,” James said.

His original brace “felt like a 10-pound dumbbell,” and although he’s pleased with his newer model, James plans to “ditch it” by the Sept. 7 regular-season opener at Dallas. “The new one, it’s comfortable and I’ll use it as a weapon,” James said half-jokingly.

James dislocated the same elbow in college at Oregon, and before last month’s injury, he was poised to take over as the No. 2 running back after Kendall Hunter’s season-ending knee injury.

Bruce Ellington and Perrish Cox fielded punts in the 49ers’ previous two exhibitions. Ellington has coped with an injured middle finger on his left hand since last week’s practices against the Ravens.

As for the playing surface at Levi’s Stadium, where new sod was laid Friday, James expressed no concerns.

“You’ve got to play through whatever surface you’re on,” James said. “I was in Green Bay last year and it was negative-20. I feel I can play on anything.”

Coach Jim Harbaugh said he has not gotten any indication on when the NFL will announce potential discipline of linebacker Aldon Smith, who met with commissioner Roger Goodell on Aug. 7.

Nose tackle Glenn Dorsey’s surgically repaired biceps is expected to keep him out 3﻿1/2 months, making him the 49ers’ prime candidate to receive their injured reserve/designated-for-return tag, Harbaugh said. Dorsey would be ineligible to play the first eight weeks of the season if he receives that designation, putting his return as early as Nov. 2 against the St. Louis Rams.

Safety Antoine Bethea was medically cleared to return from a concussion and wore a no-contact jersey in practice, but he won’t play Sunday, Harbaugh said.

Linebacker Patrick Willis and nose tackle Mike Purcell wore no-contact jerseys for the second straight practice for undisclosed injuries.

Right tackle Anthony Davis (shoulder) suited up in full for the first time at practice since last season.

Michael Crabtree practiced for the first time since attending Monday’s birth of his son, Michaell III, in Texas.