A year after supplanting Isaac Seumalo as the Eagles' left guard, Stefen Wisniewksi lost his job last week.

He said he found out the Monday or Tuesday after the Titans loss that Seumalo would return to the starting lineup for the Vikings game. The Eagles still lost. Afterward, Wisniewski was asked if he had received an explanation for the change.

"I'm going to be honest: I've been playing pretty well," he said. "I don't think that was it. I have some theories, but I'm not going to share those publicly."

Wisniewski doubled down and tweeted out a similar message Monday. Eagles coach Doug Pederson, later in the day, said he didn't know what the 29-year-old lineman's theories could be and discounted the notion that he could be pressured by the front office to play Seumalo because he's a former high draft pick.

"Everything in this business is performance-based," Pederson said.

The coach didn't go into detail when asked why Seumalo got the nod. Any objective evaluator would say that Wisniewski hasn't dominated. The same could be said of the Eagles' entire offensive line. But after watching every block this season, it would be stretch to say that Wisniewski deserved to get benched.

The Eagles might have just been looking for a spark, and with Seumalo in his third season and seemingly more confident, now might have been as good a time as any to make a change. But Wisniewski was demoted for significantly less than Seumalo was last year when he allowed four sacks in the Chiefs game.

It took only one series for Seumalo to give up a sack this year. But he rebounded and played solidly the rest of the Vikings game. Pederson wouldn't rule out another change, but with the short week, Seumalo is expected to start Thursday night at the New York Giants.

Should the initial change have even been made? Here's a closer look at Wisniewski in the first four games and Seumalo on Sunday:

RUN BLOCKING

Wisniewski (No. 61) is a better pass protector than run blocker. He's not especially big (6-foot-3, 305 pounds), but he makes up for what he lacks in size with good technique. Run blocking requires more brute strength than pass blocking. On this run play against the Falcons in Week 1, a slap knocked Wisniewski off balance.

He isn't very athletic either, but Wisniewski compensates with a high football intellect. He brings a center's mentality to guard and does well with blocking assignments. On this Jay Ajayi (No. 26) rush later in the Falcons game, he teamed up with left tackle Jason Peters (No. 71) before getting to the second level.

Wisniewski does well with angles and leverage. On this outside zone run, he got his hands on the down lineman and turned him inside as Corey Clement (No. 30) ran by him for a 15-yard touchdown against the Buccaneers.

The Eagles will sometimes pull linemen on their inside zone runs. Because he's not massive like right guard Brandon Brooks (No. 79) or quick like center Jason Kelce (No. 62), Wisniewksi must be more exact when moving into space. He struggled on this pull in the Colts game.

He rarely misses assignments, but on this stretch run against the Colts, Wisniewski appeared to miss his guy.

Wisniewski: I missed a block here or there. But it's the NFL.

There are far more examples of Wisniewski getting it right, as he showed on this Wendell Smallwood (No. 28) carry against the Titans.

His run blocking could have been the reason given for his demotion, but the Eagles haven't had issues on the ground other than they haven't the run the ball as much as they did last season or haven't been able to.

PASS BLOCKING

Wisniewski didn't allow a sack in the first four games. He allowed only one last season, according to Pro Football Focus. He does a good job of keeping his hands down early in a rush. NFL defensive linemen feast on quick hands. On this play against the Falcons, Wisniewski waited until the tackle showed his hand before locking in.

Here he is handling a bull rush against the Colts.

Quarterback Carson Wentz had a clean pocket and hit Zach Ertz downfield for 28 yards.

Wentz: Isaac or Wiz, whoever's in there, honestly, I'm extremely confident in either of those guys.

Wisniewski had some early struggles against the Titans. He wasn't the only one. But on the Eagles' opening drive, defensive tackle Jurrell Casey (No. 99) slipped by the guard and hurried Wentz into a bad pass.

He finished strong and kept Casey, one of the best at his position, in check, as he did here on this 24-yard strike to Ertz.

HANDLING GAMES

Kelce: Right now on the offensive line there hasn't been too many times where a guy just got flat out beat on his own. You see a lot of games happening. So we have to get back on the practice field and work on games. We have to work on passing things off, taking the correct set line so that you are in the position to work with your person next to you.

"Games," or stunts or twists are switches between two linemen as they rush. In the Bucs game, Wisniewksi and Halapoulivaati Vaitai (No. 72), who had replaced the injured Peters, successfully navigated this game.

On this play, Peters was late and Wentz was hit again in the Titans game.

Wisniewski has started 21 games at left guard for the Eagles over the last three seasons, 14 by Peters' side. Chemistry is important. Peters has clearly lost a step. While he technically hasn't allowed a sack this season, the nine-time Pro Bowl tackle has been inconsistent.

Wisniewski: Teams are always going to do what's in their best interest. It's not necessarily in the interest of any individual player.

ISAAC SEUMALO

Seumalo struggled on the Eagles' first series vs. the Vikings. On three straight rushes, defensive tackle Linval Joseph walked him back into Wentz. The last resulted in a sack.

Pederson: He had one bad snap in there but overall, played pretty well.

Peters: It's going to take a couple of weeks. Isaac is going to be just fine. That's the first time I played with him since the Kansas City game last season. We didn't do badly for the first time around.

Seumalo settled down after the Eagles schemed protection to his side for a few drives. On the strip sack that resulted in a Joseph fumble returned for a touchdown, he squared up the tackle until the ball popped into his hands.

Seumalo spent most of the spring and summer at center. That is his natural position and likely where he projects best. But the Eagles like his versatility.

Pederson: We felt comfortable with his versatility playing all five positions, which he's very capable of doing. He's a year older. He's done well in practice and he has earned an opportunity to play, and so we felt like this past week it was a good opportunity.

The Eagles also like his ability to move in space, as well, as he did here on this outside zone.

Eagles offensive coordinator Mike Groh: He [has] … a lot athleticism. [He has] played with a lot of confidence and is able to not only hear the calls, but make calls and recognize things outs there on the run.

But will he be better than Wisniewski and will he hang onto the job, unlike last year?

Wisniewski: It's frustrating. If I wasn't a Christian, I'd probably be losing my mind. … I'm going to keep a good attitude, keep working, and be ready to go.