DRAFT COUNTDOWN: 3 weeks. Every Friday until the April 27-29 draft, we look at draft topics related to the Seahawks.

Whether the Seahawks trade Richard Sherman or not this year, the admission by Pete Carroll and John Schneider that the Hawks are fielding offers for the All-Pro is a sign that the Legion of Boom is at a crossroads.

Even if Earl Thomas comes back better than ever, Kam Chancellor gets his contract extension and Sherman avoids a trade, it is clear the end is approaching for the fabled unit. And, as it turns out, this is a great year to find heirs apparent in the draft.

The Legion’s core trio is approaching age 30 — Chancellor and Sherman just turned 29 and Thomas will be 28 in May — and a combination of ongoing injuries and attitude issues means it is time to look ahead.

Sherman said “there is no bad blood” even though Schneider is taking calls about dealing the cornerback, but it is clear these partners are headed for a divorce soon. If it’s not this year, it seems very likely to be next year — before his contract is up. Either way, the Hawks look very certain to replace him by 2019 — and this is the draft to do it.

Chancellor seems likely to get a contract extension this offseason (if his demands aren’t outrageous), but it’s hard to see him playing more than two or three years more. He just turned 29, but his body is much older. He had minor surgery on both ankles again this offseason — just more of the surgical maintenance his body has required throughout a seven-year career full of big hits.

Thomas could call it quits at any time, too. He emotionally hinted at retirement right after his leg was broken (on a hit by Chancellor) in a game against Carolina in December. He has since rededicated himself to coming back better than ever and is on track to be ready for training camp, but that doesn’t erase the possibility that he could decide to retire at any point. He is signed for two more seasons — and will be 29 at the end of the deal.

With DeShawn Shead recovering from an ACL injury and not expected to be a big factor in 2017, it is clear the Seahawks need to add some defensive backs.

Cue the draft.

The Seahawks seem immensely interested in a possible Chancellor heir: Connecticut’s Obi Melifonwu. They reportedly have invested a lot of time in the athletic, 6-foot-4, 224-pounder, who seemingly has climbed into the first round.

The Hawks also have been linked to cornerbacks Kevin King (UW) and Marlon Humphrey (son of former Denver running back Bobby Humphrey), but would Carroll and Schneider really take a corner in the first round for the first time?

If they move Sherman or plan to move him by next year, the answer could be yes. They would need a more NFL-ready player than they usually draft — no Day 3 projects like Walter Thurmond, Byron Maxwell and Jeremy Lane.

Of course, the class is so deep Seattle might well find a starting corner in the second or third round, too.

Let’s look at some of Seattle’s primary options in the secondary:

CORNERBACKS
Gareon Conley, Ohio State: Another long corner (6 feet, 33-inch arms) with good speed (4.44) who could challenge for a starting spot immediately. Only weakness is run support. He’ll probably be gone before Seattle picks — unless the Hawks get into the top 20. Projected pick range: 10-20.

Marlon Humphrey, Alabama: The 6-foot son of Bobby Humphrey has the speed (4.41) and length (32 1/4-inch arms) the Hawks love. It sounds like he will need a lot of technique work both for zone coverage and playing the deep ball. Projected pick range: 20-25.

Tre’Davious White, LSU: He’s got enough length and is a solid cover guy, but he is not a good tackler and might be better suited to the slot. Projected pick range: 25-35.

Kevin King, Washington: King looks like a match made in Seattle. Tall (6-3), athletic and speedy (4.43), he perfectly fits the Hawks’ specs. Projected pick range: 25-35.

Adoree Jackson, USC: Jackson does not fit Seattle’s physical profile (5-10 with arms under 32 inches), but he could step in as the slot corner while relieving Tyler Lockett of return duties. Projected pick range: 25-35.

Chidobe Awuzie, Colorado: The 6-foot cover man is a little light on length and tackling ability for the Seahawks. But he has everything else. Projected pick range: 30-40.

Rasul Douglas, West Virginia: Douglas (6-2, 209) has the length and pick potential (eight in 2016) to be a solid Day 2 option. Projected pick range: Late second or third round.

Quincy Wilson, Florida: He has Seattle size (6-1, 211), but analysts point out he needs a lot of work in his coverage technique. Also a candidate to be flipped to safety. Projected pick range: Late second or third round.

Cordrea Tankersley, Clemson: Another guy who fits size prereqs (6-1, 199, 32-inch arms), but his ball reaction needs work (too many PI calls). Projected pick range: Second or third round.

Ahkello Witherspoon, Colorado: At 6-3 with 33-inch arms, he’s Plastic Man. And he’s fast (4.45). He needs to work on strength and technique and become more willing in the running game. Projected pick range: Second or third round.

SAFETIES
Obi Melifonwu, UConn: He’s huge (6-4, 224) and athletic and has been intriguing a lot of teams during draft season — including the Seahawks. A possible heir to Kam Chancellor? Projected pick range: 25-35.

Jabrill Peppers, Michigan: Peppers (5-11, 213) is a hybrid safety/linebacker who would need a defined role. Projected pick range: 20-25.

Budda Baker, Washington: Baker has all the grit the Hawks love and could step in as a nickel player and also offer an upgrade as Earl Thomas’ backup. Projected pick range: 25-35.

Justin Evans, Texas A&M: Physical two-way safety who would beef up depth behind Chancellor and Thomas. Projected pick range: Second round.

Marcus Maye, Florida: A good all-around safety (6-0, 210) who could contribute in a variety of ways from Day 1. Projected pick range: Second round.

DAY 3 DUD?

Despite the excellent talent at defensive back, running back and tight end, Schneider said he doesn’t like this draft as much as he liked the 2016 version.

The Seahawks don’t have a fourth (traded for Quinton Jefferson last year) and fifth (penalty for breaking offseason workout rules), but Schneider indicated this is a good year for that to happen.

“Last year I just felt like it was kind of thick all the way through and we were willing to pick players all the way through,” he said. “This year seems like there are some gaps in there … which for us not having a fourth and a fifth may work out in our favor.”

The Hawks have five picks on the first two days, and the draft seems loaded through those first three rounds. Schneider also could be eyeing another move down in the first round to add a fourth third-rounder. And he could want to move up from the bottom of the second round.

“I think there’s different parts of (the draft) that I do like,” he said, “and we want to pick in that range.”

DRAFT BUZZ

It sounds like Schneider will try to get the Raiders to give him something for Marshawn Lynch, who reportedly told the Raiders he wants to unretire and play for them. Schneider is longtime friends with Raiders GM Reggie McKenzie, dating to their days in Green Bay, and said it should be a smooth deal. Asked whether he would just let Lynch go for free, he quipped of McKenzie, “I said he’s a good friend of mine; I didn’t say he’s my BEST friend.” If a trade is made, the Hawks seem unlikely to get much more than a seventh-rounder — probably in 2018.

The Saints are the betting favorite to land Sherman, if a deal can be made. They own the 11th and 32nd picks and have been linked to the Patriots’ Malcolm Butler. But they could do better with Sherman, if they could clear cap space.

The Titans seem a better bet, if they have interest. They are an AFC team (one report said the Hawks won’t trade Sherman to an NFC team) and have two first-rounders (No. 5 and 18) and ready cap room.

The Seahawks have a history of telegraphing their second-round pick via workouts or meetings. That makes it worth keeping an eye on these players, who all reportedly have met with or worked out for Seattle: Washington FS Budda Baker, Clemson CB Cordrea Tankersley, Utah OG Isaac Asiata, Alabama DT Dalvin Tomlinson and DE Tim Williams.

MOCK DRAFTS

Pat Kirwan and Jim Miller, SiriusXM NFL Radio: OL Ryan Ramcyzk, Wisconsin.
Recap: Kirwan (longtime friend of Carroll) and Miller projected a Sherman trade to Tennessee for the 18th pick, which they used on Ramcyzk. They also made a couple more trades that netted Seattle USC CB Adoree’ Jackson and Colorado CB Ahkello Witherspoon in the early second round.
We say: It’s a pretty fanciful mock, and Ramcyzk does not seem like a pick the Hawks would make. Forrest Lamp, a likely Pro Bowl left guard, would be a better move. Two corners in the second round would blow away Seattle’s typical philosophy, but many think they will take one with one of their top two picks.

Tony Pauline, DraftAnalyst.com: CB Chidobe Awuzie, Colorado.
Pauline says: “The Seahawks like to play five defensive backs, and the versatile Awuzie can play corner, nickel and/or safety. The fact he scored a 35 on his Wonderlic at the Combine makes him that much more appealing.”
Pauline’s three-round mock also gave Seattle Missouri DE Charles Harris, Utah OG Isaac Asiata, Pittsburgh OT Adam Bisnowaty and Villanova DL Tanoh Kpassagnon.
We say: The Hawks likely wouldn’t take Awuzie without trading into the top of the second round. But he doesn’t seem like their pick either way. Harris and Asiata seem like definite possibilities.

Dane Brugler, CBSSports.com: CB Kevin King, Washington.
Brugler says: “A tall, long athlete at cornerback who played his college football in Seattle? Almost seems too obvious that he will be the pick here for the Seahawks if available.”
We say: If they are going to break tradition and pick a corner in the first round, King would seem to be a great choice.

Danny Kelly, The Ringer: S Budda Baker, Washington.
Kelly says: “Seattle needs a backup plan for Thomas — not just in case of injury this year, but also because Thomas has talked about an early retirement on a few occasions — and even if their All-Pro safety stays healthy, Baker is a playmaking ballhawk. He can feature in the slot and in nickel or dime looks for Seattle as a cornerback-safety hybrid similarly to how Arizona deploys Tyrann Mathieu.”
We say: This move would make good sense, especially if the Hawks moved down a few spots.