The Vikings are clearly rebuilding -- 52 of the 90 players in camp are in their first or second year, so there are questions to be answered throughout the roster. Chief among them is whether the problems of 2011 -- throwing the ball, defending the pass, providing solid QB protection and run-blocking up front -- have been solved.

Injuries have already impacted the team’s offseason efforts, with free agent OL Geoff Schwartz, who was brought in to bolster the right guard spot, out for 4-6 weeks with a sports hernia, and fourth-round pick WR Greg Childs, whom the Vikings had hoped would replace the suspended WR Jerome Simpson early on, lost for the season with two torn patellar tendons. But like LG Charlie Johnson said, injuries happen in the NFL and they allow the coaches to give more preseason reps to other players who are likely to contribute during the season. On this team, those younger backups will be counted on.

Questions to be answered inexhibition season:

1. Have the Vikings’ offseason moves improved one of the worst secondaries in the league? A Vikings apologist will point to injuries and other issues (Chris Cook’s legal issues and Cedric Griffin’s indifference) when looking back at the failure of the 2011 secondary, but it’s hard to ignore the numbers: 26th in passing yards (251.2 per game), tied for last in interceptions (8) -- by comparison, the Packers had 31; and contributing to a defense that ranked 31st in points-allowed per game (28.1). The Vikings will likely start second-year SS Mistral Raymond, who was forced into a starting role late last season and appears to have grown from the experience. Rookie first-rounder Harrison Smith, who plays with attitude and likes to hit, will likely press 2011 starter Jamarca Sanford for playing time. On the corners, the unit returns two players who ony played a combined 11 games last season: 35-year-old Antoine Winfield, who battled several injuries until a broken clavicle ended his season, and Cook, who returns to the lineup from off-field issues with something to prove to his teammates. The veteran Winfield will need to lead this young but talented group to improve its numbers this season.

2. With the offense in his hands, can QB Christian Ponder prove he's the team leader of the future? The Vikings have made it known since waiving veteran Donavan McNabb last season and claiming there is no quarterback controversy with Joe Webb that Christian Ponder is the quarterback of the future. But for Ponder and the Vikings, the future starts now. Ponder bulked up by 20 pounds in the offseason to protect himself from injuries (such as the several he sustained last season), and he has had a full offseason with the coaching staff to learn the playbook. He has called this Vikings team his team and he is ready to lead. But to do that, he'll have to increase his completion percentage of a year ago (54.3), improve his TD-INT ratio (13-13 in 10 starts) and learn to stick in the pocket rather than pull the ball down and run when the protection breaks down. He has received several votes of confidence from coaches -- “he's come light-years,” QB coach Craig Johnson said -- and WR Percy Harvin says Ponder has shown increased confidence and is now delivering the ball when receivers get out of break, something he wasn't doing last year. The Vikings have given Ponder more targets with the addition of TE John Carlson and speedy receiver Simpson, but reliance on the passing game will be even greater with RB Adrian Peterson still an opening-day question mark.

3. Is the revamped offensive line ready to move forward? In the recent past, the Vikings offensive line has be nicknamed the “Moving Company,” and lately that has had more to do with what they did before the snap than moving the ball downfield. The team brass moved some of the old guard out -- All Pro LG Steve Hutchinson and RG Anthony Herrera -- and moved LT Charlie Johnson to left guard. They also moved on the best left tackle in the draft, Matt Kalil, who has been given a starting job. Left right guard was left open to a competition between second-year Viking Brandon Fusco and free agent Geoff Schwartz until Schwartz when down with injury, joining several other backup linemen on the sidelines early in camp. Regardless, the result is a much younger offensive line that needs to protect its quarterback better than last season (28th in passing yards at 184.8 per game, and fifth most sacks -- 49) and open holes for the running game. Last season, the Vikings were fourth in the league in rushing (144.9 yards per game), but some of that can attributed to the fact that Peterson is arguably the best rusher in the game. This season, Peterson may not be the same player he was in the past, and the less hits on him the better. C John Sullivan, who is in his fifth season, is called on to lead the young group, and he says they are a motivated unit and eager to improve.

For the latest news and reports on the Vikings, follow Joe Oberle on Twitter @CBSSportsNFLMIN and @joeoberle.