SAN FRANCISCO - Randy Moss enjoyed a rare opportunity Friday night, getting the chance to battle against the team that drafted him in 1998 and employed him for 113 regular-season games during eight seasons.

Moss had played against the Vikings only once before. That came during the 2006 preseason while he was with Oakland, five months after the Raiders acquired the wide receiver in a trade. In that game at the Metrodome, he had one 16-yard reception.

On Friday, Moss saw limited action in the first quarter. He had no receptions and no passes thrown to him in San Francisco's 17-6 victory.

With the 49ers, the 35-year-old Moss is getting a chance to revive his career after a year away from the league. Moss has also expressed his enjoyment in mentoring a crop of talented young San Francisco receivers that includes Mario Manningham, 26; Ted Ginn, 27; Michael Crabtree, 24, and A.J. Jenkins, 22.

"It's just a feeling that I haven't really felt in a while, just being around a group of young guys, and it makes me feel good that I can really not look at my age, and just feel young," Moss told the Associated Press this week. "So I have a little pep in my step. It really feels good being around the guys."

Welcome to the NFL Rookie kicker Blair Walsh faced a potentially rough initiation into his first NFL game action Friday night. Candlestick Park's infamous gusty winds were alive and well. But Walsh handled the conditions well early on.

The rookie from Georgia capped the Vikings' first drive of the game with a 39-yard field goal that was right down the middle. He followed by putting the ensuing kickoff 5 yards into the end zone. LaMichael James opted to return the kick but was taken down at his own 16.

Walsh also nailed a 26-yard field goal to start the second quarter and followed with a kickoff through the end zone.

For a limited time only Toby Gerhart's return to California might have carried a nostalgic twist. But the Vikings running back also delivered an impressive effort, carrying five times for 31 yards, all in the first quarter.

Gerhart grew up in Norco, Calif., in the southern part of the state, where, as a high school star, he set the California record with 9,662 career rushing yards. He added 3,522 rushing yards during his college days at Stanford, about 30 miles from where Friday's game was played. Gerhart was the Heisman Trophy runner-up in 2009.

The Vikings limited Gerhart's activity Friday by design, still positioning him to be their backfield workhorse early during the regular season as Adrian Peterson works back to full health.

Secondary concerns When the Vikings emerged from April's draft, the internal belief was that they had emerged with three defensive backs -- Harrison Smith, Josh Robinson and Robert Blanton -- who could all be future starters and valuable building blocks. Yet to date, injuries have hampered two of those picks. Both Robinson and Blanton sat out Friday's game nursing hamstring problems.

Robinson, a third-round pick, pulled a hamstring during the Vikings' first training camp practice in Mankato on July 27. And while he has been back at practice this week and showing signs he is headed back toward full health, the coaching staff opted to hold him out of the preseason opener as a precautionary measure.

Blanton, meanwhile, suffered his hamstring injury on July 30 and has yet to return to practice. That has given the Vikings coaching staff very little to evaluate as they put together their plans for the 2012 season.

Etc. •The Vikings also chose to keep veteran defensive players Antoine Winfield, Kevin Williams and Jared Allen plus receiver Percy Harvin out of action for Friday's game.

•Nose tackle Letroy Guion injured a knee on the Vikings' first defensive series and did not return.