The Legion of Boom officially has been refreshed — thanks to an explosion of draft picks in Rounds 3-6.

As founding members Earl Thomas, Kam Chancellor and Richard Sherman approach the twilight of their Seattle careers and DeShawn Shead recovers from a major knee injury, one of the big goals of this draft was to add to the secondary.

The Hawks accomplished that in a big way with the selections of cornerback Shaq Griffin and safeties Delano Hill, Tedric Thompson and Mike Tyson. It is the most defensive backs John Schneider has drafted — coming after none in 10 picks last year.

The Seahawks need the help, especially with Thomas (broken leg) and Shead (ACL, MCL) recovering from injuries. Thomas is expected back during training camp, but Shead could miss the first half of the season on PUP.

The Seahawks did not end up trading Sherman — and probably won’t this year — so they need to find only one starting corner while Shead is out.

Veteran Jeremy Lane might be the favorite, but he is coming off a subpar year and the Seahawks re-signed Neiko Thorpe to a two-year deal. Griffin, the first of Seattle’s four third-rounders, figures to compete against Lane and Thorpe for Shead’s spot. (The Hawks also have DeAndre Elliott, Pierre Desir, Perrish Cox and Demetrius McCray — and Tyson apparently will move to corner.)

The Hawks love the speed, athleticism and toughness of Griffin (6-0, 194), who ran a 4.38 40 at the Combine. Griffin is aggressive and has good ball skills (six picks, 28 passes defensed in his two years as a starter at Central Florida). He also allowed just 32.9 percent completions. And he is a good run defender.

“He’s just our kind of DB,” John Schneider said.

“He had some big plays on the ball; he had plenty of good turnovers and stuff,” Pete Carroll said. “He looks just like he’ll fit in just right.”

Carroll said Griffin will play outside — a nod to competing against Lane and Thorpe. “We’ll start there and try to transition to our style of stuff. His ability to play the ball, really his ball sense too, we think he’ll be a really good fit.”

The Seahawks have loaded up at safety this offseason. The three rookies come in behind Thomas, Chancellor and excellent free-agent addition Bradley McDougald.

Hill (6-1, 216) will be reunited with former Michigan teammate Frank Clark. Hill is a thumper — perhaps a smaller version of Chancellor. He called himself “physical. I’m going to get after it. I’m going to play every down hard.”

Asked if he compares his game to Chancellor, he said, “Yes, I like to take a look from everybody, especially Kam, because he’s one of the best safeties in the league. You always want to liken yourself to one of the best safeties in the league.”

Carroll said, “He looks more like a hitter. He’s really physical. Might be a little more like Kam’s style. So we’ll see. But he’s done everything. Their scheme showed all of that. Was really a good evaluation for that and we’ve got a lot of hopes for this.”

Thompson (6-0, 204) is a ballhawking safety (seven picks, 16 passes defensed in 2016) who could be a possible backup and heir to Thomas (although Thompson doesn’t have nearly Thomas’ speed).

“I enjoy watching Earl Thomas and Kam Chancellor,” Thompson said, “and just knowing that I’m going to a team with those guys and (will) learn from those guys, it’s just a blessing.”

Schneider said Thompson has “phenomenal ball skills. … He has great feet, cover skills. He’s got really good range, really good short-area quickness.”

Tyson, meanwhile, “fits the profile” of a Seattle cornerback, Schneider said, calling him “a big (6-1, 204), tough, aggressive guy.”

“He’s primarily played inside,” Schneider said. “He played a lot of nickel for (Cincinnati last season) and got his hands on a lot of balls (five interceptions). He’s got great ball skills and is really strong in run support.”

If Griffin and Thorpe are the top contenders for right corner, Tyson could push Lane for nickel back.

Of course, McDougald figures to see a lot of action as well. The Seahawks are very excited about him and certainly will figure out how they want to get him on the field.

The Seahawks were in nickel about 70 percent of the time last season, and they might use McDougald in the “big nickel” role they experimented with Brandon Browner last summer.

Assuming Griffin, Hill and at least one of Thompson and Tyson make the team and push for playing time, the Seahawks look to have taken a good step toward fortifying their depth and setting up potential replacements if any of the three original Legionnaires move on.

Sherman seems destined to be traded next year, Chancellor will be a free agent if he is not extended and Thomas has broached the topic of retirement in the wake of a couple of tough injuries the past three years.

The LOB isn’t done yet, but the end is certainly approaching. And this draft was a good step toward establishing a good transition when needed.