The 49ers are nearing the conclusion of "football school." Next week, the helmets go on, and team offense vs. team defense periods are allowed on the Santa Clara practice field.
This is when the competition within the team will pick up.
The next three weeks will consist of 10 days of "organized team activities." And the 49ers' official offseason program will conclude June 11-13 with a mandatory minicamp.
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Here is a look at four competitions on the defensive side that will be worth watching:
The 49ers return their top five corners from a year ago. Carlos Rogers and Tarell Brown started every game for a pass defense that was exceptional during the regular season. But the 49ers' pass defense was a weakness in the playoffs due to injuries to pass-rushers Aldon Smith and Justin Smith, combined with a couple of blown coverages in the secondary.
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Third cornerback Chris Culliver had a strong second season as the No. 3 cornerback, playing more than 63 percent of the snaps during the regular season. Only 49.3 percent of pass attempts in which Culliver was targeted were completed, according to Pro Football Focus.
The biggest wild card in the 49ers' competition at cornerback is veteran Nnamdi Asomugha, a 10-year veteran who fell on hard times in his two seasons with the Philadelphia Eagles after signing a big-money contract. Many who watched him closely in Philadelphia believe he's finished, that he can no longer run with NFL wideouts.
But with his length (6 foot 2), can he still play press coverage, not allow receivers a free release and therefore disrupt the timing on pass plays to the point where quarterbacks quickly look another direction? That's what he did best during his eight seasons with the Raiders.
Tramaine Brock was the fourth cornerback a year ago, and he returns on a one-year, $1.323 million contract as a restricted free agent. Perrish Cox, who also returns, was Rogers' backup in the slot.
All Pro free safety Dashon Goldson was the only full-time 49ers starter on either side of the ball who will not return this season. It will be nearly impossible for the 49ers to come close to matching his level of play at that spot this season.
The 49ers brought in Charles Woodson for a visit. Three days later, the organization decided former St. Louis Rams safety Craig Dahl was a better investment. Then, the 49ers traded up 13 spots in the first round to select Eric Reid of LSU.
Dahl has experience with 42 career starts in five NFL seasons, including starts in all 16 games for the Rams last season. However, the Rams elected to replace both of their starting safeties from a year ago.
Reid ranked ahead of Kenny Vaccaro as the No. 1 safety on the 49ers' draft board. There will be a huge adjustment coming from college, but he has a solid pro, strong safety Donte Whitner, to be the quarterback of the secondary and help his mental game.
As far as the coverage part, rookie tight end Vance McDonald got the better of Reid in their one-on-one matchups at rookie camp. But Reid is the kind of player who should make huge leaps once the pads go on at training camp.
The starters in the 49ers' base defense appear set with left end Ray McDonald, nose tackle Glenn Dorsey and right end Justin Smith. After that, the real competition begins.
The 49ers want to create more of a rotation along the defensive line to keep McDonald and Smith from wearing down. Second-round draft pick Tank Carradine is coming off season-ending ACL surgery, but he should be ready for the start of training camp in 2 1/2 months. But as a rookie, he might be better-suited for nickel situations when the 49ers go with a four-man line.
The 49ers made the somewhat surprising decision to award third-year player Ian Williams a $1 million bonus as part of a contract extension. That indicates the team believes he can be Dorsey's backup at nose tackle. The 49ers selected 320-pound defensive lineman Quinton Dial in the fifth round.
Will Tukuafu and Demarcus Dobbs, who is rounding into shape after a season-ending knee injury, saw action on fewer than 5 percent of the defensive snaps last season. Tony Jerod-Eddie saw limited time after his late-season promotion from the practice squad. Are any of those players ready for a larger workload as the 49ers try to compensate for the free agent losses of Isaac Sopoaga and Ricky Jean Francois?
Aldon Smith and Ahmad Brooks are the starters at outside linebacker, positions they actually play less than half of the defensive snaps. (When the 49ers are in their nickel defense, both Brooks and Smith move to defensive end to rush the passer.)
Veteran Parys Haralson, a starter in 2011, missed last season with a torn triceps. He is back, and he accepted a pay cut to remain with the club for the final year of his contract. The 49ers had no confidence in their backups last season. That should change this season with Haralson's return and the addition of third-round pick Corey Lemonier.
Lemonier will compete with Haralson for the primary backup duties. Haralson is better suited for base outside linebacker, while Lemonier would likely be used exclusively in pass-rush situations as he makes the transition to standing up.
Darius Fleming and Cam Johnson will also compete for jobs. Fleming was a fifth-round pick last year whose rookie season ended with a torn ACL in rookie camp. Johnson was a seventh-round pick in 2012 who saw limited action in two games.