No. 2 - Defensive lineman Grover Stewart
Stewart had a mixed 2023 with the Indianapolis Colts because he was suspended for six games for failing a performance-enhancing drug test but when he did play he was once again very good in the areas that the Seahawks need a player to be. He is one of the better pure run-stoppers in the NFL along the interior of the defensive line. In 11 games this season, Stewart had 24 run stuffs.
But he does the same thing every season. Per PFF, Stewart does not have a grade worse than a very solid 65.2 in any season in his career. Most seasons are 70.5 or higher. He might not offer much in terms of pass rush anymore - he had 17 total pressures in 2022 and 15 in 2023 - but Seattle does not need that. Jarran Reed is still under contract and can supply interior pass rush.
PFF also has Stewart's projected contract of $10 million a year for three seasons. He is 30 years old so expecting him to still be very good in three years might be asking a bit too much, but if all Stewart is doing is excelling in run defense than he likely could still get a ton of reps on early downs, or seemingly obvious rushing downs, and be playing for four years or more.
Mike Macdonald would also make sure Stewart is not getting overused. Former defensive coordinator Clint Hurtt did a terrible job with his rotations and Reed, for example, played too much this season. Stewart would likely be kept fresh and productive in Macdonald's defense.