Quarterback Carson Wentz returns to the field for an Eagles team that has opened the season with a win and a loss under backup Nick Foles, but somehow the team's situation feels more foreboding than that lukewarm record would suggest.

When Wentz left, the victim of multiple ligament tears in his left knee last December, the Eagles were still heading to a Super Bowl win under Foles, although it definitely didn't seem that way as the sun set on the Los Angeles Coliseum that evening.

It happened, though, in the most incredible ending to a season, and one that also started with a win and a loss. The difference between the Eagles' situation after two games last season and two games this season is one of expectations.

The Eagles were supposed to progress in 2017 from their 7-9 record during Wentz's rookie year, but – what? – eight wins, nine wins, an outside shot at the playoffs? That would have been defined as progress. What happened instead, with Wentz good enough to be front-runner for the league's MVP award, raised the bar not just for the team, but also for the rest of the quarterback's career.

Eagles quarterback Carson Wentz during a game against the Giants last September.
CLEM MURRAY / Staff Photographer
Eagles quarterback Carson Wentz during a game against the Giants last September.

So, here we are, with the Eagles a quart low on skill-position players on offense and the defense coming off a stinker in Tampa Bay. It is a team that could go either way, which is what .500 usually indicates. And here comes Carson Wentz, back after nine months of recovery from surgery; strapped into a knee brace as a hedge against further injury, but wearing nothing on his back but the hopes of the franchise.

If this story came from a book with a dusty, linen cover – Chip Hilton, Gridiron Grit – then the outcome would be obvious. The Eagles will be fine and their once-broken star will be even better. What makes the real-life comeback more interesting, however, is that heroic endings aren't guaranteed.

"He'll add a spark. He's one of the best players in the league," tight end Zach Ertz said, "but we can't expect him to just put a Superman cape on and be his old self. He's going to be rusty."

Who exactly will Wentz be Sunday in Lincoln Financial Field against the Indianapolis Colts? Even his own pre-injury history isn't much of a guide. In his rookie year, he had a quarterback rating higher than 100 in three of his first four starts, but those were the only 2016 starts in which he crested that rough standard between a good and a great game.

Last season, he reversed fields. His first four games were fine, nothing great, but then he took off, achieving a rating higher than 100 in six of his last nine games, throwing 27 touchdowns and only five interceptions in that span. It was a splashy announcement of greatness, and the Eagles came together in its wake.

>> READ MORE: Thank you, Nick Foles. But it's time for Carson Wentz. | Jeff McLane

Predicting his performance after the surgery, and with the brace, and without the help of a reliable receiving or running corps, is feeling in the darkness. Other quarterbacks have come back successfully from major knee surgery. Tom Brady did it, as did Philip Rivers, Carson Palmer (twice) and others. Those pocket passers didn't have the same mobility component to their game that Wentz possessed.

Among more elusive quarterbacks, you can start with Donovan McNabb, who tore his ACL in Week 11 of the 2006 season at age 30, and came back with a strong season in 2007. His rushing numbers on scrambles were never quite the same, but he was still very good for several years. On the other side, Robert Griffin III of the Redskins never really recovered from an ACL injury at the end of his break-out rookie season.

Some Wentz watchers think that Houston's Deshaun Watson could be a reasonable comparison this season. Watson, who was a lock to be the NFL's offensive rookie of the year in 2017, tore his ACL about a month before Wentz tore his. At that point, Watson had a quarterback rating of 103.0, 19 passing touchdowns, two rushing touchdowns, eight interceptions, and a 7.5-yard rushing average.

Texans quarterback Deshaun Watson suffered a torn ACL about a month before Carson Wentz did.
Mark J. Terrill / AP
Texans quarterback Deshaun Watson suffered a torn ACL about a month before Carson Wentz did.

In two starts this season, Watson has been ordinary, although in two tough road games: a seven-point loss at New England and a three-point loss at Tennessee. Maybe he'll have better luck at home against the Giants on Sunday.

Judging Wentz against others is a walk through a hall of mirrors, of course. No two situations are the same, no two injuries are the same, and no two quarterbacks are really the same.

"I think there's going to be maybe an issue or two," coach Doug Pederson said of Wentz's return. "It's going to take some time to get back into the rhythm and the flow of the game. The speed of the game is different than the speed of practice."

Nothing is as fast as the speed of expectation, however. Having the savior quarterback once again will take the fan base from zero to 60 as soon as he emerges from the tunnel. Accelerating a football team that has responded slowly to the new season up to that same velocity might take more than a storybook narrative. It might actually take a guy worthy of that storybook. Sunday, the page will turn and we'll begin to find out.