Walker competed at the RD761 International Junior Team Cup where he finished fourth on vault and contributed to the USA's third-place finish.[2] He competed at the 2017 National Championships in the 15-16 age division; he placed fifth in the all-around and fourth on floor exercise.[3]
In August 2018, Walker competed at the U.S. National Championships in the junior 15-16 division. He placed ninth in the all-around, winning silver on floor exercise and vault and bronze on rings.[4]
2019
Walker competed at the RD761 International Junior Team Cup where he helped the USA win silver.[5] Individually he won silver in the all-around behind Takeru Kitazono and won medals on five of the six apparatuses.[6] Walker next competed at the 2019 Winter Cup where he placed first in the all-around and on vault and third on floor exercise and rings.[7]
In August, Walker competed at the U.S. National Championships in the 17-18 age division. He finished first in the all-around, on vault, and on parallel bars and second on rings and horizontal bar.[8]
2020–21
Walker became age-eligible for senior-level competition and competed at the 2020 Winter Cup. He finished 19th in the all-around.[9] Walker did not compete for the rest of the year due to the global COVID-19 pandemic.
Walker placed fifth in the all-around and third on vault at the 2022 Winter Cup.[13] He was selected to compete at the DTB Pokal Mixed Cup in Stuttgart[14] where he competed on floor exercise and vault during the preliminary round, helping the USA qualify into the championship round. The USA clinched first place in this round with his contribution on the parallel bars.[15] At the NCAA Championship Walker helped Stanford defend their national title. Additionally he placed second on parallel bars behind teammate Curran Phillips.[16]
In June Walker was selected to represent the United States at the Pan American Championships alongside Riley Loos, Brody Malone, Yul Moldauer, and Shane Wiskus.[17] On the first day of competition Walker competed on floor exercise, pommel horse, vault, and parallel bars to help qualify the United States in first place to the team final. Individually he won silver on parallel bars behind Moldauer and recorded the fourth-highest floor exercise score and fifth-highest pommel horse score.[18] During the team final Walker competed on floor exercise, vault, and parallel bars to help the USA win gold ahead of the reigning team champion Brazil.[19]
In late July Walker competed at the U.S. Classic where he placed second in the all-around behind Stanford teammate Malone with a score of 85.264 (83.750 without bonus). Additionally, he recorded the highest parallel bars score and second-highest vault score.[20] In August Walker competed at the U.S. National Championships where he finished sixth in all-around but recorded the second highest score when removing domestic bonuses. Additionally, he finished second on parallel bars and third on vault.[21]
In October Walker was named to the team to compete at the 2022 World Championships alongside Asher Hong, Brody Malone, Stephen Nedoroscik, and Donnell Whittenburg.[22] During qualifications Walker finished fourteenth on parallel bars but did not qualify for the event final. During the team final Walker contributed scores on vault, parallel bars, and horizontal bar towards the USA's fifth-place finish.[23]
2023
Walker spent the beginning of 2023 recovering from a bulging disk in his back.[24] He made his debut at the MPSF Championships where he only competed on pommel horse. He scored a 13.900, the fourth-highest score on the apparatus, and helped Stanford win the team title.[25] In April Walker competed at the NCAA Championship, once again only competing on pommel horse. He helped Stanford win their fourth consecutive team title.[26] In August Walker competed at the Core Hydration Classic where he competed the all-around for the first time this season. He placed eighth overall.[27]
At the World Championships Walker was on the competition floor supporting the team during team finals as they won the bronze medal, the USA's first team medal in nine years. As the alternate Walker was also awarded the medal.[30]
At the Pan American Games Walker helped the United States win team gold. Individually he qualified for the rings, parallel bars, and horizontal bar final.[31] On the first day of apparatus finals Walker finished fourth on rings.[32] On the final day of competition he won silver on parallel bars behind compatriot Phillips and placed fifth on horizontal bar.[33]
2024
Walker competed at the MPSF Championships where he helped Stanford place first as a team. Individually he won silver in the all-around and on parallel bars behind teammate Khoi Young. Before the NCAA Championships Walker was awarded the Nissen-Emery Award, the highest honor in men's collegiate gymnastics.[34] At the Championships Walker contributed scores on all apparatuses except pommel horse and helped Stanford win their fifth consecutive team title.[35]
