Our two-day look at NFC West rosters continues with projections for the San Francisco 49ers' offense.

Quarterbacks (4)

Average number kept since 2003: 3.1

Safest bets: Alex Smith, Colin Kaepernick, Josh Johnson

Leading contenders: none

Longer odds: Scott Tolzien

Comment: Johnson has more experience than Kaepernick and could project as the No. 2 quarterback if an injury forced Smith from the lineup on short notice. Johnson's history with coach Jim Harbaugh at the University of San Diego probably helps his chances in that regard. Kaepernick gets a chance this summer to prove he's ready to take the next step following a more regular offseason. Tolzien could project for the practice squad.

Running backs (9)

Average number kept since 2003: 4.9

Safest bets: Frank Gore, LaMichael James, Kendall Hunter, Brandon Jacobs, Bruce Miller

Leading contenders: Rock Cartwright, Anthony Dixon

Longer odds: Jewel Hampton, Cameron Bell

Comment: Moran Norris is out after spending five of the past six seasons as a 49ers fullback. That was one of many changes in the backfield this offseason. Jacobs' arrival suggests Dixon must step up his game significantly to stick on the roster -- and will probably have to demonstrate special-teams value as well. He won't be able to compete with Miller or Cartwright in that regard. If the 49ers find a way to keep six running backs, Cartwright would likely be in the picture almost exclusively for his special-teams value. Hampton could be a candidate for the practice squad.

Wide receivers (11)

Average number kept since 2003: 5.7

Safest bets: Michael Crabtree, Randy Moss, Mario Manningham, A.J. Jenkins

Leading contenders: Kyle Williams, Ted Ginn Jr.

Longer odds: Brett Swain, Joe Hastings, Nathan Palmer, Chris Owusu, Brian Tyms

Comment: The first four appear set as long as Moss continues on his current trajectory. The 49ers kept five at the position in Week 1 last season. Despite talk of opening up the offense, the team could have a hard time justifying six roster spots for wideouts for a coaching staff that seems to relish using multiple tight ends. Williams and Ginn carry obvious special-teams value in the return game, a huge consideration. I have a hard time envisioning the 49ers, stung by Williams' miscues in the NFC Championship Game, taking undue chances in the return game at Green Bay in the opener. Ginn is the most proven return specialist on the team and a game-breaker when healthy. Owusu could be a candidate for the practice squad.

Tight ends (5)

Average number kept since 2003: 2.9

Safest bets: Vernon Davis, Delanie Walker

Leading contenders: Nate Byham, Konrad Reuland

Longer odds: Garrett Celek

Comment: Byham was emerging as a top-flight blocking tight end before a knee injury ended his 2011 season during training camp. Reuland, then an undrafted rookie, had a chance to gain ground while spending last season on the practice squad. Reuland played for Harbaugh and staff at Stanford.

Offensive linemen (15)

Average number kept since 2003: 9.0

Safest bets: Joe Staley, Mike Iupati, Jonathan Goodwin, Alex Boone, Anthony Davis, Daniel Kilgore, Joe Looney

Leading contenders: Mike Person, Jason Slowey

Longer odds: Derek Hall, David Gonzales, Garrett Chisolm, Chase Beeler, Kenny Wiggins, Al Netter

Comment: Boone has become the prohibitive favorite to start at right guard even though he remains in the early stages of a conversion from tackle. Boone could move back to tackle if the 49ers were to lose Staley or Davis to injury. Boone remains the third-best tackle on the team. Kilgore once stood as a candidate at right guard, but he now projects as Goodwin's eventual successor at center. Looney, a rookie fourth-round choice, could be the long-term right guard, but he's recovering from foot surgery.