Glasgow’s guard up as Lions’ Tomlinson, Dahl challenge

Justin Rogers
The Detroit News

Over the next several days leading up to the start of Lions training camp, Justin Rogers of The Detroit News will highlight the key position battles. Today: Left guard.

Detroit — For some, the Detroit Lions left guard competition is cut and dry. It’s assumed, after closing out last season as the starter, Graham Glasgow will slide back into the role to start the 2017 campaign.

While the second-year man out of Michigan is certainly in pole position as training camp gets underway, the Lions intend to give Laken Tomlinson and Joe Dahl an opportunity to wrestle the job away from Glasgow.

Tomlinson, a first-round pick in 2014, was replaced by Glasgow after struggling through the early stages last season. The former Duke standout has had an unexpectedly rough transition to the professional game, struggling to show the necessary consistency demanded of his position.

If Tomlinson falls short of winning back his job, it’s tough to see a future in Detroit beyond this season. He was drafted by the previous front office, so general manager Bob Quinn isn’t tied to the lineman’s success.

Still, the team is on the hook for a guaranteed salary this year and releasing (or trading) Tomlinson would trigger a bigger cap hit than if the Lions keep him on the roster.

The bonus is he offers an insurance policy for T.J. Lang, who is working his way back from offseason hip surgery, on the right side. Tomlinson played right guard in college and arguably performed at this best last season when filling in for Larry Warford at that spot.

Dahl is the longshot, but the Lions have been impressed with his progress following what Quinn essentially called a developmental season for last year’s fifth-round pick. He’ll get plenty of reps in practice and during the preseason games.

After Taylor Decker went down with a shoulder injury, the Lions briefly gave Dahl an audition at left tackle, but the June additions of Greg Robinson and Cyrus Kouandjio signified the end of the experiment and Dahl will slide back inside to start camp.

Glasgow, a third-round draft pick last year, was originally viewed by most as a strong contender for the starting center job in 2016, but was easily bested in that competition by incumbent Travis Swanson.

Although Glasgow hadn’t played guard in a game for a few years, he stepped into a starting role in Week 6 and improved the play the Lions had been getting from the spot. But he was far from dominant, prone to the typical rookie mistakes.

Football analytics site Pro Football Focus graded him significantly below average as a pass protector and run blocker. That’s why the door is open. Of the returning starters along the line, Glasgow has the most to prove.

The added challenge, for all three, will be performing at their best with some unfamiliar teammates operating on their left shoulder as the Lions seek the ideal replacement for Decker. Improved play from the left guard spot — whether it’s Glasgow, Tomlinson or Dahl who provides it — could go a long way to softening the devastating loss of Decker.

Lions camp battles

Day 1:Left tackle

Day 2:Nickelback

Day 3:Fourth, fifth receivers

Day 4:SAM linebacker

Day 5: Left guard

Saturday: Fourth, fifth defensive ends

Monday: Fourth running back

Tuesday: Backup defensive tackles

Wednesday, July 26: Backup quarterback