. Undrafted, Tennyson attended
Western Michigan University where he played three seasons of NCAA Division I college hockey with the
Western Michigan Broncos men's ice hockey team. On March 30, 2012, Tennyson, a native of
Pleasanton, California, signed a two-year entry-level contract with his hometown
San Jose Sharks. He immediately turned professional to join the
Worcester Sharks for the final games of their
2011–12 AHL season. Tennyson was the first player from the San Jose Junior Sharks youth hockey program to play in the NHL, let alone with the Sharks. On July 3, 2016, Tennyson signed as a free agent to a one-year, two-way contract with the
Carolina Hurricanes. Beginning the
2016–17 season with AHL affiliate, the
Charlotte Checkers, Tennyson was recalled after recording 7 points in 9 games to remain with the Hurricanes for the remainder of the season. He appeared in a career best 45 games, collecting 6 assists. On July 1, 2017, Tennyson was on the move as a free agent, agreeing to a two-year contract with the final year on a one-way basis with the
Buffalo Sabres. On November 30, the Sabres placed Tennyson on waivers after 14 scoreless games with the club. He went unclaimed and was reassigned to AHL affiliate, the
Rochester Americans. On July 1, 2019, Tennyson left the Sabres as a free agent to sign a two-year, two-way contract with the
New Jersey Devils. In the opening stages of the
2019–20 season, on October 11, Tennyson was called up from the Binghamton Devils to the New Jersey Devils in place of
Andy Greene who was put on the
injured reserve list with an upper body injury. On July 28, 2021, Tennyson signed as a free agent to a two-year, two-way contract with the
Nashville Predators. Tennyson featured in 8 regular season games with the Predators through the season, posting 3 assists. He played the majority of the season with AHL affiliate, the
Milwaukee Admirals, adding a veteran presence to the blueline in 53 games. On July 3, 2022, Tennyson was mutually released from the remaining year of his contract with the Predators after he was placed on unconditional waivers. On September 1, 2022, it was announced that Tennyson signed for the
Coachella Valley Firebirds inaugural season in
Palm Desert, California, for the 2022–23 season. On January 30, 2024, it was announced via Instagram that Tennyson would be joining the Coachella Valley Firebirds broadcast team as an analyst and brand ambassador, effectively ending his playing career. ==Career statistics==