In his fifth year in the AFL system, O'Brien had a career-best season in 2022, playing 19 games for the much improved Blues side while showing encouraging form on the wing.
Selected with the 10th pick in the 2017 National Draft, O'Brien played 35 games in his first two seasons before only managing to feature a combined six times in the next two years.
In need of a big year, the 22-year-old averaged 17.7 disposals and 5.2 marks this year and appears set to continue to feature regularly in the navy blue for at least the next couple of seasons.
Making his debut in Round 3 this year, defender Jordan Boyd was able to play seven games in his first full season before a foot fracture cut his year short.
The 23-year-old was selected in 2021's Mid-Season draft by the Blues after eye-catching performances for Footscray in the VFL and was given his chance in 2022 after several key defensive figures succumbed to injury for Carlton.
In his seven appearances, Boyd was impressive, averaging 11.3 disposals, three marks and 228.9 meters gained and showing the club glimpses of his ability in the Blues' back six.
— Carlton FC (@CarltonFC) September 6, 2022
Speaking to carltonfc.com.au, Carlton Head of List Management Nick Austin said the re-signings were a testament to the pair's hard work and on-field performances, with the duo seen as an important part of the club's future.
"Lochie's work rate this year has seen him rewarded for effort with some strong on-field performances," Austin said.
"It's not easy solidifying your spot in that midfield group, but Lochie has proven that he can play his role and has become a vital member of the side.
"The potential that Lochie has shown this season has been really promising and he'll continue to put in the work over the next two years to build himself into a well-rounded player at the elite level.
"Jordan's ability to inject energy into the side is fantastic, and he stood tall on multiple occasions throughout the year.
"His dedication to his craft is impressive, and we've been thoroughly impressed with Jordan throughout his shrot time here.
"It was cruel to see Jordan's season cut short after just breaking into the side, but he will be ready to attack pre-season and put in the work to do everything he can to earn his place in the side."