Long attended Morgan City High School under Jeremy Whittington. As a senior, he averaged 21.4 points, 15.2 rebounds and 9.1 blocks, helping team to a 26-5 record. He was named district MVP, earned first team all-district honors for two straight year and was the district defensive player of the year as a senior.
College career
Long originally enrolled at Mississippi State University of the Southeastern Conference, but became immediately unhappy with his choice. After the first semester, and without playing in any games, Long transferred to Louisiana–Lafayette and received an NCAA waiver to allow him to play the following season without sitting out the customary full year. Long first suited up for the Ragin' Cajuns in the 2012–13 season, averaging 15.5 points and 10.2 rebounds per game to earn Sun Belt Conference Freshman of the Year and second-team All-conference honors. Over his next two seasons, Long would again average a double-double and was named first-team All-Sun Belt both years. For his senior season, Long was named the preseason Sun Belt Player of the Year. On January 23, 2016, in a game against the Troy Trojans, Long scored his 2,000th point and became the first player in school and conference history to record 2,000 points and 1,000 rebounds for his career. He was also selected for the National Association of Basketball Coaches college All-Star game to be held at the 2016 Final Four in Houston.
Professional career
Delaware and Philadelphia (2016–2017)
After going undrafted in the 2016 NBA draft, Long signed with the Philadelphia 76ers on July 8, 2016. He was waived by the 76ers on October 24 after appearing in seven preseason games. Five days later, he was acquired by the Delaware 87ers of the NBA Development League as an affiliate player of the 76ers. On January 6, 2017, Long had 45 points and 14 rebounds in a 129–105 win over the Erie BayHawks. He was selected to play in the 2017 NBA D-League All-Star Game. On March 6, 2017, he was called-up by the 76ers, who signed him to a 10-day contact to help the team deal with numerous injuries. Philadelphia had to use an NBA hardship exemption in order to sign him as he made their roster stand at 16, one over the allowed limited of 15. He made his NBA debut that night, recording 13 points and seven rebounds in a 112–98 loss to the Milwaukee Bucks. On March 16, 2017, he signed a partially guaranteed, multiyear deal with the 76ers. Seven days later, in a 117–107 win over the Chicago Bulls, Long had 18 points in just his ninth career game. On June 28, 2017, Long was traded to the Houston Rockets in exchange for a 2018 second-round pick and cash considerations. He was waived by the Rockets on September 26, 2017.
China and G League (2017–2018)
On October 10, 2017, Long signed a two-month contract with the Xinjiang Flying Tigers of the Chinese Basketball Association. He left the team in mid-November after averaging 12.7 points and 6.1 rebounds in seven games. On December 18, 2017, Long was acquired by the Delaware 87ers of the NBA G League.
On September 5, 2018, Long signed with the New Zealand Breakers for the 2018–19 NBL season. He averaged 18.3 points, 8.9 rebounds and 1.5 blocks per game and was named to the All-NBL Second Team. In May 2019, Long had a one-game stint with Guizhou Guwutang Tea of the Chinese NBL.
