We are less than 18 months from the Cubs’ 2016 World Series win.

But of the 25 Cubs who brought that victory, just 15 remain. That’s actually a good thing; teams can’t remain static, even championship teams. Players age, retire, leave as free agents, get traded.

And over the weekend, we learned that one of the biggest contracts in Cubs history has been given by the team, a contract that we hope will lead the Cubs to more World Series championships. The roster turnover, though, might be a thing of the past, at least for a while.

We still don’t have all the details of Yu Darvish’s six-year, $126 million contract with the Cubs. One thing we do know is this:

Go to bed in Korea. Wake up and Yu Darvish is a Cub. I can add this bit of news: Darvish’s opt-out comes after the second season of his six-year, $126 million contract, source familiar with it tells Yahoo Sports. @Ken_Rosenthal had the deal first. — Jeff Passan (@JeffPassan) February 10, 2018

If Darvish does opt out after two years, I think we can safely assume those would be top-notch, fantastic years, perhaps Cy Young caliber, and having a pitcher that good would make the Cubs serious World Series contenders both in 2018 and 2019. If he doesn’t opt out, well, then the performance wouldn’t be quite that good, although it could still be very good (perhaps All-Star caliber, as he was from 2012-14).

Further, Darvish has a full no-trade clause, at least for part of this contract:

source: yu darvish has a no-trade clause like jason heyward's. full no-trade for part of the deal, then switches to 12-team list. #cubs — Jon Heyman (@JonHeyman) February 11, 2018

What this also does is set the Cubs’ rotation in stone for at least the next two years. Here’s the contract status of the five pitchers now expected to be in the Cubs’ rotation this year:

Yu Darvish: signed through 2023, opt-out after 2019

Jon Lester: signed through 2020, team option for 2021

Jose Quintana: signed through 2018, team options for 2019 & 2020 (that will definitely be exercised)

Kyle Hendricks: arb-eligible 2019 & 2020, free agent after 2020

Tyler Chatwood: signed through 2020

Get used to seeing those five guys make starts for the Cubs, as they will make the bulk of them for the next two seasons — maybe even three seasons, if Darvish sticks around past his opt-out.

But that’s not true only for the rotation. Look at the contract status of the eight most likely Cubs relievers on Opening Day 2019:

Brandon Morrow: signed through 2019, team option for 2020

Steve Cishek: signed through 2019

Pedro Strop: signed through 2018, team option for 2019

Brian Duensing: signed through 2019

Mike Montgomery: arb-eligible 2019, 2020, 2021, free agent after 2021

Justin Wilson: signed through 2018

Carl Edwards Jr.: arb-eligible 2019, 2020, 2021, 2022, free agent after 2022

Justin Grimm: arb-eligible 2019, free agent after 2019

As you can see, there’s only one pitcher of the 13 likely on the 2018 Opening Day roster who’s a free agent after this year — Justin Wilson. There could be a change or two among some of the others, particularly Grimm, who’s not likely going to be back in 2019 unless he has an exceptional 2018. (I’d expect him to be non-tendered next winter if he has another bad year.)

And looking at the 12 position players who will be in Miami this March 29, the same thing applies:

Anthony Rizzo: signed through 2019, team options for 2020 and 2021 (that will almost certainly be exercised)

Javier Baez: arb-eligible 2019, 2020, 2021, free agent after 2021

Addison Russell: arb-eligible 2019, 2020, 2021, 2022, free agent after 2022

Kris Bryant: arb-eligible 2019, 2020, 2021, free agent after 2021

Ben Zobrist: signed through 2019

Tommy La Stella: arb-eligible 2019, 2020, free agent after 2020

Kyle Schwarber: arb-eligible 2019, 2020, 2021, free agent after 2021

Albert Almora Jr.: not arb-eligible until 2020, free agent after 2022

Jason Heyward: signed through 2023, opt-out after 2018 (which will probably not be exercised)

Ian Happ: not arb-eligible until 2021, free agent after 2023

Willson Contreras: not arb-eligible until 2020, free agent after 2022

Chris Gimenez: on minor-league deal, likely a free agent after 2018

You’ll note three players above have four arb years: Bryant, Edwards and Russell. This is due to service-time issues, well-known in Bryant’s case.

It’s possible the Cubs will move on from TLS after 2018, as in his second year of arbitration he’s likely going to get expensive. They will also probably have a different backup catcher in 2019; Gimenez is 35 and here on a one-year deal. Perhaps Victor Caratini takes that spot in 2019, or maybe they trade Caratini and go and find another veteran backup for Contreras.

As you can see, other than those two and maybe a couple of bullpen pieces, this 25-man roster is going to look very much the same in 2019 as it will in 2018, with at least 20 of the 25 almost guaranteed to return. And unlike most teams, who have one or two “position battles” during spring training, the 25 men named above are almost certainly going to be the 25 who will be on the roster Opening Day in Miami. This mlb.com article, which has one “burning question” for each of the 30 teams, has a player-related question about 29 of them. For the Cubs, writer Anthony Castrovince asks about the impact of the new coaching staff.

Lastly, I thought I’d mention this news item from Sunday night here, as I don’t want to devote an entire article to it:

The Chicago Cubs were down the road with Yu Darvish, but before they completed a deal, Cubs baseball president Theo Epstein, respectfully, put in one last call to the Cubs’ star free agent Jake Arrieta for one last, long-shot chance to see if — if need be — they could extend Arrieta’s career with a deal believed to be similar to the one offered to Darvish should Darvish turn them down. By that point, Epstein was happy to be closing in on the deal with Darvish at a compromise price. Darvish most recently had been seeking $125 million for five years, but in an agreement reached this weekend that will comfortably keep them below the luxury-tax threshold took $126 million for six. But Epstein felt like he owed Arrieta that call to gauge that possibility. After all, not only had Arrieta put together one of the great half-seasons in baseball history to win a Cy Young, he’d come up big time and again when it counted most and was a key figure in the Cubs’ historic 2016 World Series championship.

The honest truth is, from my standpoint, once the deal with Darvish was done (and it will reportedly be officially announced by the Cubs Tuesday), it doesn’t matter to me that Jake got “one last call.” Sure, that was a nice thing for Theo to do, but it’s done now.

When Jake Arrieta’s career is done, the Cubs will have had his best five years. He will forever be a Cubs World Series champion. Wherever he lands — and he’s likely not going to get a deal as good as Darvish’s, in my view — I wish him well.