Even as John Schneider extends core players and fills roster gaps this preseason, it is clear he is already looking intently toward the 2018 offseason.

With a bunch of players on one-year deals and half a dozen key extensions to consider next year, Schneider and contract expert Matt Thomas need to create as much financial flexibility as possible.

That explains why they used a rare (for Seattle) structure in Justin Britt’s three-year, $27 million deal: an option bonus.

According to Overthecap.com, Britt will be paid $7.75 million in 2018, but the Hawks can choose to pay $5 million as an option bonus, which means they could spread the cap hit over the three years.

The 2018 cap hit could be $9.5 million — $7.75 million salary plus $1.25 million proration from his $5 million signing bonus plus $500,000 in roster bonuses. Or it could be $6.17 million — $2.75 million salary, $2.92 million proration and the roster bonuses.

If they use the $5 million option bonus, it will give them an extra $3.33 million for the 2018 cap — but take an extra $1.17 million off 2019 and 2020.

The option bonus is not an unusual concept — teams use it in restructuring deals all the time. But the fact that Seattle is actually creating contracts with the option shows they want to be ready to zig or zag based on how their free agents perform this season.

Right now, the Hawks are projected to have around $17 million in cap space in 2018, with maybe 10 second-tier free agents behind Jimmy Graham and Luke Joeckel. They also will need to consider extensions for Earl Thomas, Tyler Lockett, Richard Sherman and K.J. Wright (Cliff Avril and Ahtyba Rubin are probably on their final big deals in Seattle, and the team might be happy to let Frank Clark go in 2019 for a comp pick).

The Hawks can easily boost their 2018 cap space. They probably will roll over around $5 million of their $8 million in remaining 2017 room, and they could consummate that Sherman trade (adding $11 million) or dump Jermaine Kearse ($5 million) and/or Jeremy Lane ($4.75 million). They also could save $3.8 million on Rubin.

Here’s a look at some other ways they will save money and be able to afford their key guys:

A Graham deal should be simple, if the Hawks want to do it. He’s already the top-paid tight end at $10 million a year. If they can redo him for $30 million over three years now, they might as well — unless they would prefer a third-round comp pick in 2019. Some have mentioned the franchise tag as a possibility, but that would mean $12 million next year (120 percent of his 2017 cap hit). It’s doubtful the Hawks will want to pay that to a 31-year-old tight end who will catch probably 60-70 passes.

Part of the thinking in keeping Joeckel at left guard probably involves the idea that it could save Seattle up to $5 million a year on an extension. He is fourth among left guards right now, at $8 million. Meanwhile, 13 left tackles make at least $10 million, with former Seahawk Russell Okung leading the way at $13.25 million with the Chargers. If Joeckel plays as well as the coaches expect, $8 million a year will be a good price for a guy who also can slide over to tackle in a pinch (except this year’s pinch, apparently).

Kearse seems destined to go, whether it’s this year or next, because his cap cash is going to go to Tyler Lockett, who could cost anywhere from $6 million to $10 million a year (depending on his 2017 performance). Paul Richardson will either be cheap to keep or make himself some money with a good 2017, which would then make him a comp factor.

If Chris Carson takes over as the starting running back at some point this season, the Hawks could go cheap at RB for three more years. Eddie Lacy would figure in the 2018 comp equation as he left in free agency, and Thomas Rawls (RFA) could be kept for cheap (or let go if he doesn’t stay healthy). Seattle could then add another back in the 2018 draft.

The Hawks are deep at corner again, even with DeShawn Shead out for half the season. With Shaq Griffin looking like a possible starter as a rookie, Neiko Thorpe signed through 2018 and Shead likely to be cheap in 2018 as he comes off his ACL injury, Sherman and/or Lane will be expendable in 2018. It’s hard to see them re-signing all three Legion of Boom originals to third deals. Kam Chancellor got his, and Thomas should as well. Sherman is the big question.

Britt was paid as a top-four center, but the Hawks see the deal as $28 million over four years because that’s what it looks like to their cap (his hit bumped up $1.25 million this year, but they can keep his salary manageable the next two years if they prefer — see the bonus discussion above).

The Hawks love their per-game roster bonuses. Britt and Chancellor have $500,000 in such bonuses in each year of their deals. Michael Bennett has $1 million in game bonuses in 2019 and 2020. Lacy has $1 million in per-game bonuses, plus his weight bonuses, plus $1.3 million in incentives. Thorpe has $250,000 in game bonuses and a $350,000 playtime/Pro Bowl escalator. Luke Willson, Oday Aboushi and Michael Wilhoite are among others with incentives and/or game roster bonuses.

The Seahawks’ 2017 draft involved all kinds of picks coming and going via trades, penalties and comps, but the 2018 draft is pretty straightforward at this point. They have made two deals involving Day 3 picks: the Marshawn Lynch trade with the Raiders and the Matt Tobin deal with the Eagles. The Hawks basically swapped a sixth for a seventh in those deals (with a fifth coming and going). So they have no pick in the sixth and two in the seventh.

The Hawks will not receive any comp picks in 2018 — they are a net plus-3 in qualifying UFAs. But all of the one-year deals, plus other pending free agents, mean they should end up with at least a couple of comps again in 2019. And, with all of their quality potential free agents in 2019, they could end up with a nice comp haul in 2020. They have received 11 comp picks in the last three years, so they know how to play that game.