3 burning questions 49ers will have entering training camp

Question No. 2: Which 49ers defensive backs stand out the most?

With San Francisco's uncertainties at quarterback (we'll get there in a minute), it shouldn't be a surprise that so much relies heavily on the defense and its new coordinator, Steve Wilks, who still inherits an elite unit that ranked No. 1 in scoring a season ago.

Still, the defensive backfield could be perceived as a weakness.

Veteran free safety Tashaun Gipson will turn 33 years old by the time the regular season begins. His presume replacement, rookie Ji'Ayir Brown, is a rookie. Enough said, even though he was the 49ers' top pick from this year's NFL Draft.

Cornerback Charvarius Ward is fine, but who starts on the boundary opposite him? is it third-year pro Deommodore Lenoir? Or is it another rookie, Darrel Luter Jr.? And what about the Niners' situation at nickel corner? Isaiah Oliver, a free agent brought in from the Atlanta Falcons earlier this offseason, appears to be the favorite to land the job. But second-year man Samuel Womack might have something to say about that. Same with Brown, assuming he sees a lot of field time.

Generally speaking, the more X-factors and variables a position or spot on the field has, the more things that could go wrong.

And San Francisco has a lot of variables within its secondary.