North Melbourne has re-signed Scott Thompson, Jarrad Waite, Ben Jacobs and Declan Mountford, with the four players all accepting one-year contract extensions.
The quartet's new deals will take them through to the end of the 2018 season.
Thompson, the eldest of the four, played 21 games in 2017, notching his 200th AFL match in Round 23 against Brisbane.
Waite once again struggled with injury and ill-discipline, but proved a key player for the Roos when on the park, kicking 22 goals in 10 games.
“We’re delighted Scott is on board again for 2018. He is a first-class defender and a great role model to have around the club, especially for the younger players coming through,” North's General Manager of Football Cameron Joyce said.
“Jarrad has been outstanding for us in his 47 games at North.
“Although he experienced a few setbacks with injury this past season, we know what he is capable of when he’s fit and firing and believe he has plenty of quality football to offer.
“On top of their on-field ability, both Scott and Jarrad are very important as we continue to develop our young talent.”
Jacobs failed to add to his career tally of 77 games in 2017 due to injury, while Mounted debuted in Round 1 in his second season at the club, before going to play 12 matches.