SANTA CLARA -- Frank Gore and Adrian Peterson are among the NFL's best role models for running backs looking to overcome career-threatening knee injuries.
They are also the 49ers' and Minnesota Vikings' workhorses, and regardless of how much they play in Sunday night's exhibition game at Candlestick Park, they are an inspiration to 49ers rookie Marcus Lattimore.
Lattimore, who's rehabilitating from a three-ligament tear, called it "definitely inspirational and motivating" to watch Peterson last season. The Vikings star returned from a December 2011 knee injury to rush for a league-high 2,097 yards and win his first NFL MVP award.
Lattimore has never had any contact with Peterson, "but hopefully I get a chance to speak to him after the game." Meanwhile, Lattimore has learned a lot from Gore through his work ethic and "just by watching him."
Gore's history of overcoming his anterior cruciate ligament tears in college at Miami also helped fueled Peterson's road to recovery last year.
"To come back from a severe injury and to perform at a high level, you don't see many guys that do that, and do it with the same confidence," Peterson said in a recent phone interview.
Peterson and Gore don't know each other on a personal basis -- "I don't talk to other guys in the NFL, just my teammates," Gore said -- but their mutual respect is strong.
"I've loved his running style," Peterson said of Gore. "He's a physical back, so smooth and a north-south guy. What I love most is his attitude. He hits the hole and is the grinding back you want."
Gore returned the compliment, saying of Peterson: "I love his game. You can tell how hard he trains and how much he loves it."
Peterson will make his exhibition debut against the 49ers, setting the tone for what he hopes will be a 2,500-yard rushing total this season.
"I didn't mean to cause too much of a ruckus," Peterson said of that goal. "It's cool. I've set the bar high for myself and the guys in front of me."
Three games into last season, the 49ers limited Peterson to a season-low average of 3.4 yards per carry (25 attempts, 86 yards) in the Vikings' 24-13 win.
"My body really got broken in that game," Peterson said.
Peterson's body got a more serious test in 2012 training camp. After practice, he had a few bowls of seafood gumbo, then his eyes began to itch and throat began to swell. A Vikings trainer promptly treated the previously unknown shellfish allergy, using an EpiPen to inject Peterson's right thigh with a dose of epinephrine.
"If EpiPen was not there, there's no telling what the outcome could have been," said Peterson, who's promoting an anaphylaxis preparedness campaign called "Show Us Your EpiPens." (Mylan Speciality will donate $25 for every photo uploaded of people using an EpiPen, via www.25YearsofEpiPen.com, and up to $25,000 will go to nonprofit allergy groups.)
Aside from Peterson and Gore, here are five other things to watch in the game:
1. Five-man pitching staff: Coach Jim Harbaugh said Friday he intends to play all five 49ers quarterbacks, and that will be a tough task if Colin Kaepernick plays longer than the one-series stints he had in the first two exhibition games. Colt McCoy is slated to be first off the bench, then look for B.J. Daniels, Scott Tolzien and newcomer Seneca Wallace -- allegedly.
2. Baldwin's debut: In case you missed Jon Baldwin in a Kansas City Chiefs uniform in the last exhibition game against the 49ers, here's your chance to see him make his 49ers debut, having been traded for a fellow first-round disappointment in A.J. Jenkins. Baldwin will be the tall chap wearing No. 84.
3. Tight end trilogy: Aside from starter Vernon Davis, the 49ers are curious what their other tight ends can offer. Rookie Vance McDonald should return after missing the last exhibition game with an apparent hamstring injury. MarQueis Gray is coming on strong and is trying to make the roster as an undrafted rookie, as Garrett Celek did last year.
4. Fishing for a snapper: Rookie Kevin McDermott apparently isn't here just to give 14th-year NFL veteran Brian Jennings a break with exhibition duty. Harbaugh called it a "very, very even" competition, and Jennings admirably has approached it as such.
5. Coverage woes: Last game, the Chiefs exhumed the 49ers' kickoff and punt coverage breakdowns from last season. Can Bubba Ventrone or Kassim Osgood solidify a roster bid as purely a special-teams ace?
Minnesota (0-2) at 49ers (1-1),
5 p.m. NBC