Draft preview: Versatile O-linemen in middle rounds

With every starter under contract for at least two more years, the Green Bay Packers' offensive line should be a strength for the foreseeable future.

Even through an inactive free agency period, Packers general manager Ted Thompson was resourceful in re-signing right tackle Bryan Bulaga. The Packers had among the NFL's five best offensive lines last season. Continuity should make it an even better unit in 2015, but the Packers still have reason to add an offensive lineman in next week's draft.

Along with talent, the offensive line's success last season came with good fortune. The Packers' first-team offensive line started 15 of the 16 regular-season games. Counting playoffs, the Packers had the same starting unit in each of the final 16 games.

Maybe good fortune will happen again in 2015, but it's unwise to take health for granted. Injuries are part of football, especially in the trenches. Moving forward, the Packers' offensive line could benefit from adding depth.

"I'm with you," former Cleveland Browns general manager and current Senior Bowl director Phil Savage said after reviewing the Packers' depth chart. "Although on paper they have everybody back, they could definitely use some help on offensive line."

The Packers have 12 offensive linemen on their roster: four guards, three tackles, three centers and two swingmen. JC Tretter, a fourth-round draft pick in 2013, has played tackle and guard and was slotted to be the team's starting center last training camp. Don Barclay, who signed undrafted in 2012, has started 18 games at right tackle and is the top backup at both tackle positions.

Barclay's and Tretter's greatest value is versatility, and they are the top two backups. Both can be counted on to avoid a crippling drop-off should a starter have an injury. But both are injury prone themselves.

Barclay is coming off a torn ACL suffered last training camp, costing him all of 2014. Recovery from an ACL injury is never a certainty, though medical advances have made it more manageable. Tretter lost his starting job to Corey Linsley after fracturing his left knee in the preseason, an injury that cost him eight games.

The Packers probably won't draft an offensive linemen in the first three rounds, but starting in Round 4 they may look to target prospects who have value in their versatility.

Wisconsin tackle Rob Havenstein could be one option. Havenstein started 41 straight games at right tackle for the Badgers, helping pave the way for tailback Melvin Gordon's record-breaking run to Heisman Trophy finalist. Havenstein (6-foot-7, 321 pounds) is projected as a right tackle, but there are some who believe he could develop as a guard.

Havenstein did not test well at the combine, ranking 55th among tackles with a 5.46-scond, 40-yard dash. On film, he shines with solid technique and a knack for always taking the proper angle.

"I'll be honest with you, I did not expect to like him as much as I did when I studied the tape," ESPN NFL draft analyst Todd McShay said. "From covering college football, doing a couple of Wisconsin's games, I don't know how to say it nicely — it's not real pretty. … He doesn't have the greatest body. You look at the combine pictures and you're like, 'Ugh, is this guy really a legitimate prospect?' You look at his numbers, they're not great.

"But then you put on the tape and it's just, over and over and over again, he finds a way to get in position, he takes the right angle and he's just grinding it out and figuring out a way to finish. I get it, he's a 5.46 guy in the 40 and he's not a great athlete, but somehow and someway he gets there. He's a much, much, much better football player than he is athlete."

After film study, McShay said, Havenstein earned a mid-third-round grade. McShay expects him to be taken in the draft's second day, before the Packers likely would get serious about drafting a lineman.

If Havenstein does slip to the fourth round or later, the value could be too good to pass up.

"I just really appreciated him studying his tape," McShay said, "and the more I watch, the more I like him. At first, I really thought that I was going to end up giving him a late-round grade and move on, and wound up giving him a mid-third-round grade. I think he belongs in Day 2 of the draft, and I think he's got a chance to become a starter in the league.

"It'll be interesting to track his career and see if he can overcome some of the physical limitations. I'm not going to bet against him, I'll put it that way."

South Carolina tackle Corey Robinson could provide good value starting in the fifth round. At 6-foot-7, 324 pounds, Robinson is a massive, physical blocker in the run game. He lacks athleticism as a pass blocker against elite edge rushers, but he has a chance to develop into a starting-caliber right tackle or guard.

"He has elite size," ESPN NFL Draft guru Mel Kiper said. "Big kid. Huge kid. Can he handle quick guys? Does he bend well enough? Does he have the feet? I think all those things will be important for him to show, or else you're talking about a Day 3 type of pick for him."

Another likely Day 3 pick is Florida center Max Garcia, who started his career at Maryland before transferring. Like Tretter, Garcia has the ability to play all three positions. He's listed as a center but could add immediate depth at both guard spots as well.

"From what I understand, in the scouting community he's picked up some traction as the process has unfolded here," Savage said. "He's somebody that fits that description."

— rwood@gannett.com and follow him on Twitter @ByRyanWood

THE MARKET

Rising stock

Florida State center Cameron Erving didn't start the pre-draft process as a first-round candidate, but with versatility he could sneak into the first day.

Falling stock

Texas A&M tackle Cedric Ogbuehi started the 2014 season as a potential first-round pick, but an ACL tear has dropped him on draft boards.

Sleeper

Florida tackle D.J. Humphries has raw technique and skills that need to be further developed, but his pure athleticism could make him a starting left tackle.

Top 10 offensive tackles

1. Brandon Scherff, Iowa

Height: 6-5. Weight: 319. Class: Senior. 225 bench: 22 reps. Projection: Round 1.

•The consensus top offensive tackle in the draft may actually be better suited to play guard, drawing comparisons to Dallas Cowboys offensive lineman Zach Martin.

2. La'el Collins, LSU

Height: 6-4. Weight: 305. Class: Senior. 225 bench: 21 reps. Projection: Round 1.

•A better run blocker than pass protector, Collins could start immediately at right tackle and has the ability to slide over to the left side with further development.

3. Andrus Peat, Stanford

Height: 6-7. Weight: 313. Class: Junior. 225 bench: N/A. Projection: Round 1.

•Peat's massive frame is the first thing that stands out, but he adds surprising quickness and athleticism to his tremendous size.

4. Ereck Flowers, Miami

Height: 6-6. Weight: 329. Class: Junior. 225 bench: 37 reps. Projection: Round 1.

•Flowers is as strong as they come, highlighted by his impressive showing on bench press at the NFL combine.

5. D.J. Humphries, Florida

Height: 6-5. Weight: 307. Class: Junior. 225 bench: 26 reps. Projection: Round 1.

•Humphries may be the most athletic of the tackle prospects.

6. T.J. Clemmings, Pittsburgh

Height: 6-5. Weight: 309. Class: Senior. 225 bench: 22 reps. Projection: Rounds 1-2

•If Clemmings slides into the first round, it would be more based on potential than NFL readiness.

7. Jake Fisher, Oregon

Height: 6-6. Weight: 306. Class: Senior. 225 bench: 25 reps. Projection: Rounds 1-2.

•With the draft approaching, no tackle has moved up boards quicker than Fisher.

8. Cedric Ogbuehi, Texas A&M

Height: 6-5. Weight: 306. Class: Senior. 225 bench: 23 reps. Projection: Round 2.

•Durability is a significant concern with Ogbuehi, who is coming off a torn ACL injury that won't be healed until after the draft.

9. Donovan Smith, Penn State

Height: 6-6. Weight: 338. Class: Junior. 225 bench: 26 reps. Projection: Round 2.

•His size is a plus, but better fundamentals would allow Smith to better maximize his physical talent.

10. Daryl Williams, Oklahoma

Height: 6-5. Weight: 327. Class: Senior. 225 bench: 27 reps. Projection: Rounds 2-3.

•Williams may never be ready to play left tackle, but he could develop into a solid starting right tackle.

Top 5 interior offensive linemen

1. Cameron Erving, Florida State

Height: 6-5. Weight: 314. Class: Senior. 225 bench: 30 reps. Projection: Rounds 1-2.

•Athletic, versatile player who started his college career on the defensive line, started at left tackle for a national championship team, and may project best in the NFL as a dominant center.

2. Laken Tomlinson, Duke

Height: 6-3. Weight: 323. Class: Senior. 225 bench: 25 reps. Projection: Round 2.

•Not the most athletic prospect, but could make a real impact for an offensive line as a run blocker.

3. A.J. Cann, South Carolina

Height: 6-3. Weight: 313. Class: Senior. 225 bench: 26 reps. Projection: Round 2.

•Powerful, downhill blocker who could be dominant in the running game, though he could use more mobility for pull blocks.

4. Tre' Jackson, Florida State

Height: 6-4. Weight: 330. Class: Senior. 225 bench: 20. Projection: Rounds 2-3.

•Jackson projects as an immediate starter at guard, though his technique could use further refinement.

5. Hroniss Grasu, Oregon

Height: 6-3. Weight: 297. Class: Senior. 225 bench: N/A. Projection: Rounds 2-3.

•Grasu is not a dominant run blocker but his athleticism allows him the versatility to fit in multiple schemes.