Grant Cohn: Five 49ers who could excel in Chip Kelly’s offense

Dead last in points. Second to last in yards. Second to last in first downs. Second to last in third-down-conversion percentage. And second to last in red-zone scoring.

That's where the 49ers' offense ranked compared to the rest of the NFL last season. We're talking one of the worst offenses in the history of 49ers offenses. Will next season's offense be any better?

On the surface, it looks worse. It lost two of its best players — Alex Boone and Anquan Boldin — and replaced them with cheaper alternatives. Replaced Boone with Zane Beadles, who will make roughly a third of what Boone will make the next few seasons with the Vikings. And replaced Boldin with Eric Rogers, a former CFL player who has just $225,000 guaranteed in his contract.

The Niners also signed a backup quarterback — Thad Lewis. He, Rogers and Beadles were the only free agents from other teams the Niners signed.

The Niners must believe new head coach Chip Kelly is the big addition. Must believe Kelly can take almost the same roster and create a significantly better offense than last season. And there's probably some truth to that. Compared to Geep Chryst, the previous offensive coordinator, Kelly is Bill Walsh.

Here are five unproven players who could have breakout seasons in Kelly's offensive system.

1. QB Blaine Gabbert.

Last season, Gabbert started eight games and completed a career-best 63.1 percent of his passes. This offseason during three OTA practices open to the media, Gabbert has completed 68.6 percent of his passes. Big improvement. Kelly's offense seems to bring out the best in the Niners' quarterback.

Kelly features short passes to wide receivers running slants and shallow crosses, touch passes to tail backs running screens and swing routes, and the occasional deep pass to a tight end running up the seam. Gabbert throws all of these passes well. He likes these passes.

He does not particularly like throwing passes downfield near the sideline. Doesn't like to challenge cornerbacks. Fortunately for Gabbert, Kelly isn't asking him to.

2. TE Vance McDonald.

McDonald was a bust the first two and a half seasons of his career because Colin Kaepernick didn't trust him to catch his rocket passes. Wouldn't even throw him the ball.

As soon as Kaepernick got benched last season, McDonald became a major contributor in the offense. Caught 24 passes, gained 304 yards and scored three touchdowns during just seven games playing with Gabbert. Which means McDonald was on pace to catch 55 passes, gain 695 yards and score seven touchdowns if he had played 16 games with Gabbert. Good numbers for a tight end who has shaky hands.

McDonald may put up even better numbers next season. He has a quarterback who trusts him, plus a coach who will feature him in the passing game. When Kelly coached the Eagles last season, he featured Zach Ertz who caught 75 passes. McDonald almost surely will play the Ertz role, which is 'H-Back' — the tight end who lines up in the slot. McDonald played that position in college.

3. WR Bruce Ellington

With McDonald playing the role of Ertz, Ellington will play the role of Jordan Matthews, the Eagles' slot receiver who caught 85 passes and scored eight touchdowns last season under Kelly.

Ellington hardly played under Chryst, because Chryst didn't feature a slot receiver in his offense. He featured three tight ends. Kelly almost never plays that many tight ends at once.

Kelly prefers using three wide receivers. In his offense, the slot receiver often starts, and typically is a possession receiver who runs 'bubble screens' and crossing routes over the middle. Ellington runs these routes well.

During OTAs, Ellington clearly was Gabbert's favorite receiver. Remember, Gabbert likes throwing short passes over the middle, so Ellington is perfect for him. Don't be shocked if Ellington catches more passes next season than Torrey Smith, whom most experts consider the Niners' No. 1 receiver.

4. RB Shaun Draughn.

Kelly's backup running back usually is a receiving specialist. Last season in Philadelphia, Kelly's backup running back was Darren Sproles who caught 55 passes.

Kelly's current offensive coordinator, Curtis Modkins, uses backup running backs similarly. Last season, Modkins coached running backs for the Lions, and their No. 2 back, Theo Riddick, caught 80 passes.

Draughn could match that total next season. With Gabbert at quarterback, Draughn caught 25 passes in just six games last season. He was on pace to catch 67 passes for a full 16-game season.

I recently asked Modkins if Draughn and Riddick are similar.

'Yeah,' he said. 'They're similar.'

'What does Draughn do well?' I asked.

'Shaun can do everything well,' Modkins replied. 'He gives you some versatility. He gives you the ability to create matchup problems and things like that. So, they're very similar players. I'm excited about it.'

5. OT Fahn Cooper.

The Niners' starting right tackle during OTAs was veteran Erik Pears, a savvy, experienced played who struggled at right tackle last season. He was much better when he played guard.

Pears also seemed to struggle at tackle during OTAs this offseason. On Thursday, second-year defensive end Arik Armstead pushed back Pears seven yards during a pass play. Pears couldn't stand his ground. He probably won't be the starter when the season begins.

Pears' backup, Trent Brown, may not start either. He can't even get on the practice field this offseason. He weighs 355 pounds and seems out of shape. He doesn't have the endurance to play in Kelly's hurry-up offense. Kelly needs a new right tackle.

Rookie fifth-round pick Fahn Cooper might become that player next season. Cooper was fantastic during Thursday's OTA, blocking fellow rookie fifth-round pick Ronald Blair, a defensive lineman who was one of the strongest players in this year's draft.

If Cooper continues to play well during training camp and OTAs, he could start as early as Week 1 against the Rams.

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.