Gary Lee Striewski was born on January 11, 1987, in Denver, Colorado, to a Polish-American father and a Korean mother. He attended Metropolitan State University of Denver, where he earned a Bachelor of Science in Broadcast Journalism. After graduating, he began his broadcasting career as a weekend sportscaster at CBS affiliate KGWN in Cheyenne, Wyoming. He went on to work as a sports reporter and anchor at KPRC in Houston, Texas, and at CBS Northern Colorado 5 before joining NESN in Boston.

At NESN, Striewski became the primary Boston Red Sox sideline reporter beginning in 2013 and also co-hosted the children’s program NESN Clubhouse. He departed NESN in January 2017 and briefly co-hosted Morning Dose, a CW morning show, alongside Laila Muhammad and Melissa Rycroft. ESPN hired him in March 2018, where he initially anchored multiple SportsCenter editions before becoming a key figure in ESPN’s digital expansion.

During his tenure at ESPN, Striewski has anchored SportsCenter on Snapchat and co-hosted The Elle Duncan Show, Hoop Streams, Rankings Reaction, and Formula 1 pre- and post-race shows. Since March 2025, he has co-anchored the weekday 7 a.m. SportsCenter: AM alongside Randy Scott. He also co-hosts SC+, ESPN’s daily SportsCenter show exclusively for Disney+.