The same holds true for second-round pick LaMichael James. For now he's stacked behind Frank Gore and backups Kendall Hunter, Brandon Jacobs and Anthony Dixon at halfback. The 49ers also have fullbacks Bruce Miller and Rock Cartwright thrown into the mix at running back.
Fourth-round pick Joe Looney and sixth choice Jason Slowey will be thrown into a five-headed race for right guard with incumbents Daniel Kilgore, Mike Person and Alex Boone. It's a race Looney and Slowey are unlikely to win. There also has been talk about starting right tackle Anthony Davis being thrown into the mix at right guard as the 49ers look to get their five best offensive linemen on the field.
Linebackers Cam Johnson and Darius Fleming will compete for playing time on special teams and both will push for being a situational pass rusher. But each of those rookies will need to show well to even make the team.
Sixth-round choice Trenton Robinson is probably the safest of the late-round choices to make the team because the 49ers need a fourth safety.
However, all the rookies will get their chance to challenge for playing time, and here are some of the veterans who could be threatened by the rookies:
Running back Brandon Jacobs: Even if LaMichael James never plays a snap this season, the 49ers will have him on the roster. Both coach Jim Harbaugh and general manager Trent Baalke said the team could keep seven running backs and fullbacks and that means Gore, Hunter, Dixon, James, Miller, Cartwright and then Jacobs. However, Jacobs and Dixon could be locked in a battle for a playing spot if the team decides it can't carry five running backs. Jacobs is at a disadvantage because he doesn't play special teams. Also Dixon could possibly play fullback, which Jacobs has never done. Cartwright is considered mainly a special teams core player, but his spot on the team could be threatened if rookies Fleming, Johnson and Robinson proved to be worthy special teams players.
Wide receiver Kyle Williams: With the offseason additions of Moss, Manningham and now Jenkins, the team might also carry six wide receivers when considering incumbents Ted Ginn Jr., Michael Crabtree and Williams. That, of course, would affect how many players the team can carry at running back, which will be a consideration when the numbers at these two positions finally are considered. Harbaugh and Baalke speak glowingly of Williams despite his punt return gaffes that figured prominently in the NFC championship game loss to the Giants. Nevertheless, Williams is talented, and he's perfectly suited as a slot receiver. But he'll have to prove himself to make the team. The addition of Moss, Manningham and Jenkins could also push Crabtree out of the starting lineup for the first time since his arrival in 2009.
Linebacker Tavares Gooden: A backup linebacker and special teams denizen, Gooden is not considered to be a valuable backup at inside linebacker. If Fleming proves to be more adept and can replace Gooden on special teams without a drop off, Gooden could be in trouble.
JUST LIKE THE REST OF THE NFL, the 49ers were struck by the death of former All-Pro linebacker Junior Seau.
Here's coach Jim Harbaugh's take. He spent his final year in the NFL with the Chargers in 2000, when Seau was in his prime on his way to being selected to the All-Pro team for the 10th consecutive year.
"The qualities I most respected in Junior were the caring and respect he showed to all those with whom he came in contact," Harbaugh said. "One of my fondest remembrances as a professional football player was looking across the locker room after playing my last career game with the Chargers and knowing that I had shared that moment with one of the greatest teammates and competitors the game has ever known. The moment moved me to get off my stool, approach Junior and ask him to trade jerseys. It's the only time I had done that in my career."
IN AN INTERVIEW WITH KNBR, the 49ers' flagship radio station, freshly drafted running back LaMichael James revealed one reason for picking Oregon as his college of choice.
"I would not go to two or three colleges just because they were Adidas," James said. "Weirdest thing ever. I was just like, 'Uh, they're Adidas.' I wouldn't go to Arkansas and I wouldn't go to Mississippi State because they were Adidas schools -- No three stripes for me. All Nike."
WIDE RECEIVER RANDY MOSS JOINEDwhat's known as the "second phase" of the team's offseason workout program.
The second phase allows coaches to watch workouts, and they saw Moss, sporting his traditional No. 84, catching passes from Alex Smith and other quarterbacks.
Moss was not present for the first phase of workouts earlier in April.
"It was eye opening," Moss told the team's website. "Today was the first day, and we were moving so fast. Today felt like we'd been out here for a week or two."
Phase two workouts are voluntary, but almost the entire team showed up to participate. One exception, however, was running back Frank Gore. Over the last couple of years, Gore has stayed in his native Florida to conduct workouts.
TOP DRAFT PICKS JENKINS AND JAMES will miss significant parts of the team's offseason practices.
Jenkins will miss the 49ers rookie camp May 11-13 in order to walk with classmates during graduation at the University of Illinois, where he's a communications major.
James won't graduate until mid-June because Oregon is on the quarter system, which will make him miss the rookie minicamp and three separate OTA practices.
"It's always good to have that degree," James, a sports business major, said this week in his radio interview. "We're always one snap away and that's true for everybody. You can't play football forever."
THE NINERS SIGED THREE UNDRAFTED rookie free agents from coach Jim Harbaugh's former team at Stanford.
The top prospect of that group is wide receiver Chris Owusu, who impressed at the NFL Combine by running a 4.36 in the 40-yard dash and recording a 40.5 inch vertical jump. However, Owusu did sustain three concussions in a 13-month span.
The team also signed Stanford defensive tackle Matt Masafilo and safety Michael Thomas. Masafilo signed right after the draft ended Saturday and was already at team headquarters in Santa Clara – not far from the Stanford campus – later that afternoon.