Stefen Wisniewski fits perfectly with Eagles, from the seen to the unseen | Mike Sielski

So where do you want to begin with Stefen Wisniewski – the seen or the unseen?

The seen is the easier place to start. It always is. You can see, for instance, how much better the Eagles offensive line has played this season when Wisniewski has been at left guard. No more Isaac Seumalo getting bull-rushed and driven backward. No more inconsistency from Chance Warmack. Wisniewski has passed the eye test in a way those two guys haven't. (But then, he's used to passing tests. He carried a 3.9 grade-point average at Penn State.)

You can see the statistics and trends that hint at Wisniewski's importance to the line and the entire Eagles offense. He played in 12 games, sitting out the season's first two as the Eagles gave Seumalo, a third-round draft pick in 2016, every opportunity to secure a starting spot, then sitting out two December games because of an ankle injury before returning in the team's finale against the Cowboys. Now, a single NFL season is a pretty small sample size, open to influence from any number of factors, from the quality of the opponents to the identity of a team's own quarterback. (What, you don't think having to play Nick Foles in place of Carson Wentz doesn't change certain circumstances?) And by comparing the 12 games Wisniewski did play to the four he didn't, we're taking smaller samples of an already small sample. So, caveats abound.

>> READ MORE: Complete coverage previewing the Eagles-Falcons game

And yet … in the games Wisniewski didn't play, the Eagles averaged 87.6 rushing yards and gave up an average of 2.75 sacks for 18 lost yards. In the games he did play – and he will play in Saturday's divisional-round game against the Falcons — the Eagles averaged 147 rushing yards and gave up 2.08 sacks for 13.2 lost yards.

You can see and read (and hear, if you happen to be in the Eagles' locker room) the testaments from his teammates and coaches to his intelligence and versatility. Over his seven-year NFL career, with the Raiders, Jaguars and Eagles, Wisniewski has started at guard and center, a background that makes him particularly valuable before each snap. He's adept at and accustomed to recognizing what a defense is likely to do and reacting accordingly.

"He's probably one of the smartest players on the team," right tackle Lane Johnson said. "He's another center, so if [Jason] Kelce misses something, which he rarely does, Wiz is there to pick it up. Wiz has played a lot of football. Just having him back and in the room is like having another coach on the field."

So much for the seen. But it's the unseen stuff that's more interesting, that raises the kinds of questions that only Wisniewski himself can answer. Such as: Entering last offseason, he knew that the Eagles were high on Seumalo, that because of Seumalo's age (24) and his draft status they were likely to give him the benefit of the doubt in a one-on-one positional competition with Wisniewski (who is 28). Yet Wisniewski re-signed with the Eagles anyway – a three-year contract that could end up being worth more than $8 million – even though he could have signed with another team and started right away. Why come back?

"I looked at a lot of factors, and there were a lot of reasons to come back here," said Wisniewski, a Pittsburgh native who had never been on a playoff team before this season. "I like the organization. I like the guys, not just personally, but from a talent perspective, there's a lot of talent here. I knew we'd be able to win. Having lost a lot in my career, that was something I liked. Losing's not fun, and I definitely wanted an opportunity to win. Other than the talent, being in my home state, I liked that. And obviously, you look at the contract.

"Going back to my faith, I have prayed about it a lot, and I felt good about coming back here from a spiritual perspective."

The Eagles have several devout Christians on their roster — Wentz perhaps the most famous and overt among them — and Wisniewski is one. He came to Christianity, he said, when he was 18, after he drove his car too fast around a turn and crashed. He and his friends in the car emerged uninjured, but the accident was a kind of Damascus moment for him, except the road was somewhere near the Allegheny River.

Since then, he has found a sense of calm and self-assurance in his faith, particularly when he's not playing well. Or, as was the case early this season, when he's not playing at all.

"If you're kind of in your own head, if you start asking questions in your head — I must not be good enough; I must be doing something wrong — you start doubting, and that negatively affects your performance," he said. "But if you keep believing in yourself, keep believing in God, I think that's going to help."

In his mind, it helped him into the lineup, which in turn helped the Eagles compile the best record in the NFC. Now that Stefen Wisniewski is healthy again and will start Saturday in the most important game of the Eagles' season, make of his presence and its effect — the seen, the unseen, all of it — what you will. Just don't undervalue it.