Harrison signed with the Bird Dawgs in August 2025 after spending the first portion of the season with the Greensboro Grasshoppers, the High-A affiliate of the Pittsburgh Pirates. He appeared in 24 games with Down East, hitting .253, where he became the primary shortstop.

Harrison was selected by the Pirates in the 18th round of the 2023 MLB Draft. Following the draft, he played 18 games with Bradenton, hitting .262. In 2024, he advanced to Double-A Altoona while also seeing time with both Bradenton and Greensboro.

A native of Kailua, Hawaii, Harrison began his collegiate career at Texas A&M, where he played two seasons before transferring to NC State. In his final collegiate season, he hit .313 over 57 games. He also gained valuable summer experience in the Cape Cod Baseball League, spending one season with Harwich and one with Cotuit.