St Kilda have put their faith in the long-term commitment of Nasiah Wanganeen-Milera and Marcus Windhager, elevating the pair into the men's side's leadership group.

Both Wanganeen-Milera and Windhager put pen to paper on extensions to remain in Moorabbin last year.

Wanganeen-Milera, 22, highly touted as the competition's best emerging talent - if not already established within the league's best - was understood to have commanded lucrative long-term offers from rival club's before signing what is reportedly a deal worth $2 million a year at the Saints.

A club Next Generation Academy graduate, Windhager is locked in for the long-term through to the end of 2029.

The Saints were forced to hand captaincy over to new faces following the departure of skipper Jack Steele to Melbourne in the recent trade period.

Former rookie listers Callum Wilkie and Jack Sinclair were named co-captains on Monday.

Wanganeen-Milera and Windhager join Mason Wood and fellow first-time leader Mitch Owens in the six-man group.

St Kilda are hoping the appointment of the elevated supporting names spells commitment to the future of the club - notable given Wanganeen-Milera's limited time secured there.

"It's a positive sign for our future," Hayes said.

"Nas, Marcus and Mitch are highly competitive and deeply invested in this club. They challenge their teammates, demand accountability and bring energy every day.

"To see three young players step into leadership at this stage shows the direction our program is heading."

Wanganeen-Milera is entering his fifth season having claimed his maiden Trevor Barker Medal at the club's best-and-fairest last season. Windhager finished fifth in the count.