It's two steps forward, one step back for the Detroit offensive line. On the plus side, they added T.J. Lang and Ricky Wagner during free agency. Those additions helped them slot among our top 15 offensive lines in the magazine story. But now they're going to have to play a good chunk of the season without left tackle Taylor Decker.

Decker suffered a shoulder injury at OTAs, and underwent surgery last week. He's expected to be sidelined for four months. That will have him missing at least the first 4-6 games, and sounds like the PUP list (costing him a minimum of six games) is likely.

Jim Caldwell says he doesn't think the injury will cost Decker the entire season, which is lukewarm assurance; that can't be ruled out. Clearly Detroit will need to get by with a much lesser player than their 2016 first-rounder for a good portion of 2017.

While ranking players at each offensive line position, we had Decker as roughly a middle of the pack left tackle; maybe slightly above average. Joe Dahl is probably next man up, with Corey Robinson another possibility. For now we're ranking that player as a bottom-5 option.

LEFT TACKLE RANKINGS
RkPlayer
1Tyron Smith, Dall.
2Joe Thomas, Clev.
3Trent Williams, Wash.
4Taylor Lewan, Tenn.
5Joe Staley, S.F.
6Terron Armstead, N.O.
7Jake Matthews, Atl.
8Nate Solder, N.E.
9Donald Penn, Oak.
10Andrew Whitworth, LAR
11Cordy Glenn, Buff.
12Laremy Tunsil, Mia.
13Duane Brown, Hou.
14David Bakhtiari, G.B.
15Riley Reiff, Minn.
16Ronnie Stanley, Balt.
17Jason Peters, Phil.
18Eric Fisher, K.C.
19Anthony Castonzo, Ind.
20Russell Okung, LAC
21.Donovan Smith, T.B.
22.Branden Albert, Jac.
23.Allejandro Villanueva, Pitt.
24.Matt Kalil, Car.
25.Kelvin Beachum, NYJ
26.Charles Leno, Chi.
27.Jake Fisher, Cin.
28.Joe Dahl, Det.
29.Garret Bolles, Den.
30.Ereck Flowers, NYG
31.D.J. Humphries, Ariz.
32.George Fant, Sea.

--Andy Richardson