Grant Cohn: 49ers' top 5 draft needs

The NFL draft is less than one month away. It's time to take stock of the 49ers' needs.

They have an awful lot. I count 10 — wide receiver, tight end, running back, backup quarterback, offensive line, left defensive end, backup outside linebacker, 'Mike' inside linebacker, cornerback and backup safety. I might have missed a couple.

Let's focus on the Niners' five biggest needs. Here they are in ascending order of importance.

5. Wide Receiver

Before the 49ers signed Torrey Smith, wide receiver might have been the Niners' biggest need.

Now, the Niners have the best wide-receiver tandem in the NFC West. Last season, Boldin and Smith caught 132 passes, made 16 touchdown catches and gained 1,829 receiving yards combined. No other duo in the division came close to producing those numbers.

Boldin and Smith are a winning combination — they won a Super Bowl together with Ravens in 2013. But Boldin will be a free agent in 2016. He might not want to re-sign with the Niners, and the Niners might not want to re-sign him. He turns 36 in 2016.

The Niners should plan ahead and draft a replacement a year before Boldin hits free agency. The Niners can find a replacement in Round 3 or Round 4. Good receivers usually fall to Round 3 and Round 4.

4. Cornerback

The 49ers didn't lose one starting cornerback this offseason, they lost two. Chris Culliver signed with the Washington Redskins, and Perrish Cox signed with the Tennessee Titans.

As of now, the Niners' replacement cornerbacks are Tramaine Brock and Shareece Wright. They're solid, maybe even better than Culliver and Cox. But they're not great. They have problems.

Wright has been in the NFL four seasons and has intercepted just one pass. Brock has been in the NFL five seasons and has played just 1,125 snaps — slightly more than one full season. Last season, he played only 84 snaps.

Brock was the Niners' No. 1 cornerback last year in training camp, but he broke down as soon as the season began. Week 1, he suffered a turf-toe injury. Week 10, he pulled his hamstring.

Even if he stays healthy next season, he is not a shutdown corner. Super Bowl teams usually have one shutdown corner. Both Super Bowl teams last season had one. The Seahawks had Richard Sherman, and the Patriots had Darrelle Revis.

If the Niners want one, they'll have to draft one in the first round — corners are in demand. Unfortunately, the Niners have three needs more pressing than cornerback.

3. Offensive Line

The whole line is shaky.

It might be pretty good if Anthony Davis stays healthy and if Daniel Kilgore's broken leg recovers and if Brandon Thomas' torn ACL doesn't tear again. But that's a lot of ifs.

Here's another — if just one of those three guys gets hurt, the Niners' offensive line will crumble, just like last season.

The offensive line is the foundation of any offense. Three-fifths of the 49ers' foundation has cracks. It doesn't pass inspection. The other two-fifths aren't so sturdy, either. Joe Staley turns 31 in August, and Alex Boone will be a free agent in 2016. The 49ers rarely re-sign guards. Boone could be a goner.

The Niners need someone who can play all over the offensive line, not just one position.

2. Tight End

The Niners have the best wide-receiver duo in the division, but they also have the worst tight-end duo in the division, maybe the entire league.

Last season, Vernon Davis and Vance McDonald caught only 28 passes combined. Frank Gore and Carlos Hyde caught 30, and they're running backs.

Davis is slowing down. He is a bad route-runner who relies on speed to get open. Without speed, he's nothing. Last season, he was a poor receiver and a poor blocker. He turned 31 in January.

McDonald can block but he can't catch. He's like a second fullback or a sixth offensive lineman. When he plays, the opposing defense knows he isn't getting the ball. But he doesn't always play. He missed eight games last season with a back injury.

The Niners need a tight end, not a run-blocking specialist with a bad back. Only a few good tight ends are in the upcoming draft — Clive Walford, Maxx Williams and Devin Funchess. Experts expect them to get picked in Round 2.

1. Inside Linebacker

The Niners defense features two inside linebackers. One is called the 'Jack,' the other is called the 'Mike.'

NaVorro Bowman is the 'Jack.' Before he retired, Patrick Willis was the 'Mike.' The Niners need a 'Mike.'

The 'Mike' is a more physically demanding position than the 'Jack.' The 'Jack' has it easy. He lines up directly behind a defensive tackle — football coaches say the 'Jack' is 'stacked' behind the defensive tackle.

'Jack' is short for 'Stack Linebacker.' The defensive tackle wrestles the left guard so the 'Jack' doesn't have to. The defensive tackle protects the 'Jack,' gives him room to roam.

The 'Mike' gets no protection. He does not line up behind a defensive tackle. The 'Mike' lines up directly across from the opposing team's right guard. There is no one between them.

The 'Mike' has to be stout to absorb hits from that 300-pound right guard, and fast to cover the tight end. Only two linebackers in the upcoming draft can do both of those things — Vic Beasley and Stephone Anthony.

The Niners probably won't get Beasley. He is one of the best players in the draft, likely a top-10 pick. The Niners pick 15th.

Anthony should be available in Round 2. If the 49ers don't get him, they'll have to draft two 'Mike' linebackers — a run-stopping specialist and a pass-coverage specialist.

Grant Cohn writes sports columns and the 'Inside the 49ers' blog for The Press Democrat's website. You can reach him at grantcohn@gmail.com.