49ers season preview: Five storylines to follow

The 49ers have a new coaching staff, a new general manager, a whole new regime. Their job is to slowly rebuild a team that won only two games last season.

Because of a few critical veteran additions and a relatively easy schedule, the Niners could return to the playoffs as soon as this season. But a few things must go their way, especially during training camp. Here are their top five training camp storylines.

1. Teaching Kyle Shanahan's offense

In 2011 when the 49ers hired Jim Harbaugh, the league was coming off a lockout and teams didn't have OTAs or minicamp to install their plays. They had to install everything during training camp. Harbaugh installed his complex offense in just a few weeks and the 49ers won 13 games that season.

New head coach Kyle Shanahan coaches an offense that's even more complex than Harbaugh's, but also more successful. In 2016, Shanahan was the offensive coordinator for the Atlanta Falcons, and they scored the most points in the NFL.

Last season was Shanahan's second with the Falcons. During his first season, their offense ranked just 21st in points scored. That's because Shanahan's offense takes a long time for players to learn.

Can Shanahan shorten the learning curve for his players this season just as Harbaugh did in 2011? If the answer is “yes,” the Niners could be competitive.

And the answer may be “yes.” The Niners signed a few veterans who have played for Shanahan and know his system already, such as tight end Logan Paulsen, running back Tim Hightower, wide receiver Pierre Garçon and quarterback Brian Hoyer.

2. Working around Brian Hoyer's limitations

Hoyer started 16 games for Shanahan in 2013 and 2014 when both were with the Cleveland Browns. His numbers with the Browns were unimpressive. Since then, Hoyer has played for the Texans and Bears and he has improved, starting 17 games with a quarterback rating of 93.7. He has played especially well on first and second down, when his quarterback rating has been 95.5.

Hoyer thrives on those early downs. He's an excellent play-action passer who depends on the threat of the running game to create big passing windows downfield. On third down when Hoyer loses the threat of the run game and the defense knows he has to pass, he becomes much less effective.

To work around this limitation, the 49ers are constructing an offense that tries to avoid third down as much as possible. Avoiding third down is Shanahan's specialty. Last season, his Falcons offense faced the fewest third downs of any team in the league.

3. Evaluating Carlos Hyde

This is a make-or-break season for Hyde with the 49ers. He will be a free agent in 2018 and the new regime has not offered him a contract extension.

Hyde still has a lot to prove. First, he needs to prove he's durable enough to carry the offense.

He has missed at least two games each of the past five seasons dating back to his junior season at Ohio State, and he has gone on the injured reserve list twice since the Niners made him a starter two years ago.

Hyde also has to prove he fits Shanahan's pro-style offense, in which the quarterback primarily lines up under center. Since Hyde entered the NFL in 2014, he has averaged just 3.1 yards per carry when the quarterback was under center.

He is much more effective when the quarterback is in the shotgun.

If Hyde adapts to Shanahan's offense and stays healthy, the Niners will have an excellent running game and they probably will re-sign Hyde during the offseason. But if he doesn't adapt and he struggles during the preseason, they could trade him before the regular season even begins.

4. New defensive coordinator

Training camp will be as much of a learning experience for the 49ers' new defensive coordinator, Robert Saleh, as it will be for their players.

Saleh has never been a coordinator. He was a linebackers coach for the Jacksonville Jaguars the past three seasons and a defensive quality control coach for the Seattle Seahawks from 2011 to 2013. He is only 38 years old.

Saleh comes from Pete Carroll's tree of coaches, and Carroll is one of the best defensive minds in the league. The Niners are hoping Carroll taught Saleh well. But Saleh still has a lot to learn on the fly.

He has to learn how to install a defense during training camp, how to make weekly game plans, how to make halftime adjustments and how to call plays.

And he has no one to help him. The head coach has an offensive background. Saleh is on his own.

5. Depth at inside linebacker

Last season, the Niners had almost no depth at inside linebacker.

Now, they have three players who can start - rookie Rueben Foster, free-agent signee Malcolm Smith and veteran NaVorro Bowman. Those three will compete for two jobs.

Bowman is the most accomplished of the three, but he's coming off a torn Achilles tendon, which he suffered only nine months ago.

Ordinarily, a player in his position would work very little during training camp, but Bowman doesn't have that luxury. He has to compete.

How hard will the 49ers push him during training camp and preseason? They can't afford to go easy on him. They need to know exactly how good he is so they can arrange their depth chart.

Bowman probably will play only 12 snaps the first preseason game, and maybe 20-24 snaps during the second preseason game. But during the third preseason game, which usually is the dress rehearsal, he should play at least the entire first half and the first series of the third quarter.

If he doesn't play well during the preseason, not only could he lose his place in the starting lineup, he also might lose his job with the team.

The Niners could release him rather than bury him on the bench. Bowman's career is on the line.