Uchiyama started his career with Kawasaki Frontale before enrolling at the Tokai University.[2] Following his graduation, he signed to Japan Football League side Tokyo Musashino City. Having only made one appearance for the Tokyo-based side, he signed for J-League side Roasso Kumamoto. His career with Roasso did not kick off immediately, and he had to wait three years before making his debut in J3 League on 27 June 2020, playing the entirety of a 3-2 win against Kagoshima United.[3]
^"【熊本】「見返してやろう」。Jデビューを狙うGK内山圭、古巣との再会" [[Kumamoto] "Let's look back." Goalkeeper Kei Uchiyama aiming for J debut, reunion with old nest]. soccermagazine.jp (in Japanese). 24 January 2020. Retrieved 13 January 2021.
^"1ショット日記「飛躍」" [1-shot diary "Leap"]. kawasakisodachi.net (in Japanese). 22 October 2020. Retrieved 13 January 2021.