Born in a military hospital in Germany, where his parents were serving in the US Air Force at the time, Keene attended Earl Warren High School in his hometown of San Antonio, Texas. He scored over 1,600 points in his career and graduated as the school's all-time leading scorer. During Keene's sophomore and junior years combined he scored 781 points, and in his senior season alone he scored 869. Keene's junior year saw him get named to the all-state, all-city, and Super-City Team. In Keene's senior season, he averaged 25 points, four rebounds, and four assists per game. He only had one Division I scholarship offer heading into his senior year, Youngstown State, which he accepted.
College career
Keene's freshman season at Youngstown State saw him have moderate success. He averaged 6.5 points per game in 22 games played, including one start. He totaled 149 points on the year. In 2014–15, his season was "up and down," but he performed well by averaging 15.6 points per game, which led the team and was sixth-highest in the Horizon League. At one point he was suspended for breaking a teammate's nose, and his overall satisfaction was not high; Keene wanted to play point guard but had been designated as a spot-up shooting guard. After a game against Central Michigan, whose up-tempo offense and "free-wheeling" style of play appealed to Keene, he had a conversation with a Central Michigan assistant coach. Keene then chose to transfer shortly thereafter. In 2015–16, Keene had to sit out his first season at Central Michigan due to NCAA transfer eligibility rules. During that season he played as a scout teamer against the starters but he frequently dominated them. One time, Keene scored 37 points against them in a scrimmage. Fellow guard Braylon Rayson said, "We couldn’t do nothing with him. It was to the point where we just had to live with it." Keene exploded onto the nationalcollege basketball scene when he became eligible in 2016–17. Through YouTube-worthy highlights, SportsCenter Top 10 game-winning shots, and his nation-leading scoring average, sports media have paid attention to him. On January 21, 2017, Keene scored 50 points against Miami, including 10 made three-point field goals. It was the highest single game scoring output by anyone in Division I that season. On February 9, he was named as a top-20 finalist for the John R. Wooden Award, given annually to the nation's best player. Keene finished the 2016–17 season averaging 30.0 points per game, becoming the first player to average at least 30 points since LIU Brooklyn's Charles Jones during the 1996–97 season 20 years earlier. On March 14, it was announced that Keene would test his 2017 NBA draft stock, with him having the option to return to Central Michigan before the NBA draft lottery is set. One month later, Keene signed an agent, thus ending his collegiate eligibility.
College statistics
Professional career
Dinamo Academy Cagliari (2017–2018)
After going undrafted in the 2017 NBA Draft, he joined the Washington Wizards for the 2017 NBA Summer League. After failing to be signed to a regular season contract with the Wizards, Keene signed to play in Italy's Serie A2 Basket league for the Cagliari Dinamo Academy. He averaged 18.8 points, 4.5 rebounds and 2.9 assists over 30 games in his first season.
