The Biggest Question Mark Remaining in the 49ers Starting Lineup

Among the huge question marks in the 49ers' starting lineup this year, quarterback certainly is one of them.

But the 49ers will start either a serviceable veteran who wins more than he loses or an extremely talented 22-year old who was the No. 3 pick in last year's draft. So the 49ers should be covered at quarterback.

It's unclear whether they're covered at center.

The 49ers still haven't said whether Alex Mack will play this season or retire. And if he hasn't made his mind up by mid May, it seems unlikely he will return. And if he doesn't return, what is the 49ers plan to replace him?

They could move Daniel Brunskill to center and create a question mark at right guard.

They could start Jake Brendel, who has started three games in his career.

They could start sixth-round pick Nick Zakelj, who never has played center.

They could start Dohnovan West, who's a rookie undrafted free agent.

Or they could start Jason Poe, another rookie undrafted free agent who might be better suited to play fullback.

It seems if Mack retires, the 49ers are prepared to have a huge, batte-royale-style training camp competition for the starting center job between five players who might not be particularly good.

A better plan would have been to sign a quality center during free agency. But to do that, the 49ers would have had to cut Jimmy Garoppolo and create cap space, something they apparently are unwilling to do.

So they'll have to hope a starting-caliber center emerges out of nowhere.