So much has changed since Alex Smith last started for Washington. The offense might, too.

The past two years have been anything but easy for Smith after he endured 17 surgeries and months of rehab to recover from a gruesome leg injury. It seemed fated to end his NFL career. At one point it nearly took his life.

Yet on Sunday, when Washington plays the Lions in Detroit, Smith will continue his remarkable comeback and start his first game in 728 days. And this one will have a drastically different feel from his last one.

“It obviously has been a long time, even just driving into work with that feeling knowing that the ball’s in your hands and preparing all week like that,” he said. “It has been a while since I’ve had that feeling, almost two years to the week. It’s different. It’s a different deal.”

As Washington tries to rebuild under Coach Ron Rivera, Smith is already its third starting quarterback of the season. He is working with a first-year play caller in Scott Turner and a starting unit that, excluding him, averages only about three seasons of pro experience; running back Antonio Gibson was 7 years old when Smith was a rookie.

Even more bizarre: At 2-6, Washington is vying for a playoff spot, trailing by just a game and a half in the lackluster NFC East — while also trying to find an identity and future quarterback.

“Obviously a lot has happened since two years ago,” Smith said. “Not just for myself but certainly for all of us and the conditions that we’re in right now.”

Although the system is familiar to Smith — he played for Norv Turner, Scott’s father, with San Francisco — the offense Washington first rolled out with Dwayne Haskins was later tweaked to better suit the skill set of Kyle Allen in Week 5. When Allen suffered an ankle injury in the first quarter of Washington’s loss to the New York Giants on Sunday, it was inevitable the offense could change again.

“We knew the second [Smith] came in, the game plan was going to change slightly from what Allen would have done,” Giants Coach Joe Judge said after his team’s win.

Scott Turner agreed “to a certain extent.” Yes, Washington’s offense appeared different when Smith took over against the Giants. But even Smith appeared different from his first outing, and the flow of the game dictated many of the changes.

The same offense that amassed 208 rushing yards in Week 7 carried the ball only nine times against the Giants. But it also used run-pass options at a higher rate than it had in the previous three games, totaled a season-high 407 yards and had four completions of more than 30 yards.

Quarterback? Or circumstances?

“There’s not a huge difference. Both guys are cerebral guys,” Turner said of Allen and Smith. “They’re going to read the defense; they’re going to get the ball where it needs to be. The game plan that we had prepared all week, that was the game plan for them that obviously was geared a little bit more toward Kyle. But Alex is more than capable of doing all that stuff.

“Alex, credit to him, is a guy that — as a No. 2, you’re not getting a lot of reps through the week. You’re getting a couple here and there, but it was Kyle. I called it as if he was ready to play because I know Alex is a pro and he was prepared even without the reps. For the most part, he executed. Obviously, there were some plays that he would like back, but he gave us a chance to win that game.”

Smith had 325 passing yards in the loss to New York but also three interceptions, including two that ended Washington’s shot at a comeback win late in the fourth quarter. Rivera has pushed back against any insinuation that Smith was the primary reason for the team’s loss, arguing instead that mistakes were shared by all three phases.

“Those were plays that he tried to force as opposed to trying to take what he would’ve gotten if they had been normal downs,” Rivera said of Smith’s last two interceptions. “Again, he played pretty doggone well. … I’m not sure if judging him on those last two interceptions was fair.”

How much Washington’s offense will change — and how much Smith’s play itself will evolve — going forward remains to be seen. But perhaps the most noticeable difference, at least initially, will come from his week of preparation.

Unlike his first two games this season, when he came off the bench after taking limited reps in practice, Smith will get all the practice reps with Washington’s first-team offense this week. He will get a clearer visual of the defensive looks he might see Sunday and gain a better rhythm with his receivers and backs. He will get a better feel for anticipating throws and various scenarios. He will get a game plan geared more toward him — and probably with significant input from him.

And he will resume a role that once was so familiar but now is different. A different kind of challenge.

“I’ve said this a bunch,” Smith said, “but certainly why I chased this coming back, that feeling of being on the line, toeing the line, putting yourself out there with this game and how important every week is, it’s an amazing feeling. I love the challenge.”

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