Gates, who notably averaged 20.6 points, 7.7 rebounds, and 4.1 assists per game in his senior season at Kent State, signed as an undrafted free agent with the San Diego Chargers in 2003. He quickly moved from a third-string player to a starter, making his first NFL catch in Week 4 and scoring his first touchdown in Week 10 of his rookie season. His breakthrough year came in 2004, where he recorded 81 receptions for 964 yards and 13 touchdowns, initially tying and then breaking the NFL single-season record for touchdown receptions by a tight end. Gates built a distinguished 16-season NFL career, spent entirely with the San Diego/Los Angeles Chargers from 2003 to 2018.
He was also named to the NFL 2000s All-Decade Team and the San Diego Chargers 50th Anniversary Team in 2009. Antonio Gates officially announced his retirement from professional football in 2020, immediately transitioning to a prominent role as Legends Ambassador for the Los Angeles Chargers. His unparalleled career was further celebrated with his induction into the San Diego Chargers Hall of Fame in 2023, and he is slated for induction into the prestigious Pro Football Hall of Fame in 2025, a testament to his groundbreaking journey and enduring impact on the sport.