The Sooners and the Volunteers have scheduled a non-conference series.
Oklahoma and Tennessee have agreed to a non-conference series.
The Sooners and the Volunteers announced this afternoon that they've scheduled games in 2020 and 2024.
Oklahoma and Tennessee will meet in Norman on Sept. 12, 2020. The historic programs will meet in Knoxville on Sept. 7, 2024.
"The Tennessee series renews our commitment to marquee non-conference games," Castiglione said. "The games in 2014 and '15 demonstrated a tremendous respect between two storied programs, as well as between a pair of passionate fan bases, and so for the players, coaches and fans, we're excited to renew this high-profile series.
"In signing the contract for this new series, we worked together to allow for other conflicts. That's the reason we are not playing in back-to-back seasons."
Oklahoma and Tennessee last met in 2015 in what was a thrilling, 31-24 double-overtime victory for the Sooners.
OU's future non-conference games include: Ohio State (2017), UCLA (2018, 2019), Army (2018, 2020), Houston (2019), Nebraska (2021, 2022, 2029, 2030), Temple (2024, 2025, 2028), Michigan (2025, 2026) and LSU (dates TBA).