One of the top prospects out of Canada, Long was ranked as the 7th-best player in Canada according to North Pole Hoops. He participated in the 2011 All-Canada Classic, a showcase of the best Canadian basketball players and played for the CIA Bounce AAU program, the top AAU summer circuit in Canada. He played with NBA players Tristan Thompson and Cory Joseph, and future Cyclone teammate Melvin Ejim while competing for REDA Red in the National Prep School Athletic Association in 2011–12. Naz played for Findlay Prep in Las Vegas, Nev., during the 2010–11 season, helping the Prep Pilots to a 28–4 record and their third-straight ESPN Rise National High School Invitational appearance where he was teammates with Texas’Myck Kabongo. He prepped at Montrose Christian in 2009–10, teaming with Duke's Josh Hairston During his recruitment he received offers from Rice, Dayton, Creighton, and Miami, eventually committing to the Iowa State Cyclones.
College career
Freshman season
Naz saw action in 18 games as a freshman, averaging 1.4 points and 1.0 assists. He tallied seven points vs. Southern and handed out seven assists vs. Alabama A&M.
Sophomore season
Long played in all 36 games, making seven starts and establishing himself as a clutch 3-point threat. He averaged 7.1 points per game and shot 40 percent from behind the arc, finishing fourth in the Big 12 in 3-point field goal percentage and seventh in 3-pointers made. His 64 3-pointers ranks as the 17th-most by a Cyclone in a single season. He made at least four 3-pointers in seven games. He hit a 30-foot three at the buzzer to send the Cyclones to overtime against Oklahoma State and in ISU's game at Oklahoma State earlier in the season, Long drilled a three to send the game to triple-OT. He earned Phillips 66 Big 12 Player of the Week honors after hitting 8-of-11 3-pointers in the Cyclones' season-opening win against UNC Wilmington and finishing with a career-high 26 points in the game. He went 4-of-6 from long range to score 16 points in the Cyclones' win against No. 7 Michigan. Long played a key role in ISU's Big 12 Tournament run, making 7-of-10 threes and averaging 10 points and going 4-of-6 from behind the arc in the championship game against Baylor. In the third round of the NCAA Tournament, Long hit three 3-pointers in the final 5:10, including one that tied the game at 81, as ISU rallied to defeat North Carolina. He averaged 7.1 points per game and shot 40 percent from behind the arc, finishing fourth in the Big 12 in 3-point field goal percentage and seventh in 3-pointers made. His 64 3-pointers ranks as the 17th-most by a Cyclone in a single season.
Junior season
Long saw action in all 34 games, making 33 starts and hit four or more threes in a game six times. He scored a team-high 20 points in Iowa State's regular season win against Kansas and connected on 5-of-9 threes to lead Iowa State with 21 points in win at Iowa. He drilled 7-of-10 threes and scored a season-high 24 points against Mississippi Valley State. Naz grabbed a career-high seven boards in win against Texas. He averaged 10.1 points, 2.9 rebounds, and 2.0 assists. He hit a team-high 77 three-pointers, the eighth most in a single season by a Cyclone. He was second in the Big 12 averaging 2.3 three-pointers made per game and finished the season tied for fifth in the league shooting 39.1 percent behind the arc. Naz had ISU's third-longest streak of games with a three-pointer come to an end at 21 games. He shot 44.9 percent from the field despite 77.5 percent of his shots coming from three-point range and is tied for fifth all-time at Iowa State with 146 three-pointers made. Long suffered a labral tears in both of his hips during the season. In the offseason he had separate surgeries to repair each tear.
Senior season
Naz played in the first eight games this season for the fifth-ranked Cyclones, averaging 12.0 points in 31.6 minutes. He got a rest against Arkansas–Pine Bluff, with coach Steve Prohm commenting that his situation would be re-evaluated every week. On 15 December 2015, he decided to sit out the rest of the season due to persistent pain from his hip surgeries. Mitrou-Long commented on his decision: "I feel the need to take time off to allow myself to rehab with our training staff to get back to where I can perform at my peak level on the basketball court". Iowa State coach Prohm supported Mitrou-Long's decision to sit out to rehabilitate, while adding his belief that the team could react in a positive manner. Naz was awarded a medical redshirt by the Big 12, thus becoming eligible for the 2016-2017 season.
Going into his redshirt senior season, Long was named in the preseason All-Big 12 Second-Team, receiving praise from coach Prohm for his work ethic, maturity and leadership. Former teammate Jameel McKay commented before the season that Mitrou-Long looked in the best shape of his life, also stating that he could end up Big 12's leading scorer for the season. He started the season strong, posting his first career double-double against the Savannah State Tigers with 18 points and a career best 10 rebounds. Versus Mount St. Mary's Mountaineers, Mitrou-Long played against his younger brother Elijah Long, a sophomore for the Mountaineers; Mitrou-Long said after the game: "Part of me wanted to cheer for him. Part of me was keeping it competitive. It was a little weird, but man it was a good time". Against the Drake Bulldogs, Mitrou-Long set a new career-high in scoring with 37 points on 8 of 12 three-pointers. At the end of his redshirted senior season, Mitrou-Long would be named for the official All-Big 12 Second Team for the work he put in that year for Iowa State.
After going undrafted in the 2017 NBA draft, Mitrou-Long played for the Sacramento Kings in the 2017 NBA Summer League. He later signed with the Utah Jazz for their training camp squad. After getting cut from the team, he was assigned to the Salt Lake City Stars in the NBA G League.
Utah Jazz (2017–2019)
After showing promising results for his playing in Salt Lake City Stars, on December 22, 2017, Mitrou-Long signed a two-way contract with the Utah Jazz, taking the spot that was originally held by Nate Wolters. This move saw him split playing time between the Jazz and the Stars for the rest of the length of his contract. Mitrou-Long made his NBA debut four days later, recording a three-pointer in a blowout 107–83 loss to the Denver Nuggets. However, on January 13, 2018, Mitrou-Long was waived from the Jazz in order to sign former college teammate Georges Niang. He was re-signed by the Jazz on February 11, 2018 to a 10-day contract. After his first 10-day contract expired on February 21, he signed a second 10-day contract with the Jazz three days later.
Salt Lake City Stars (2018–2019)
On January 16, 2018, Mitrou-Long was reacquired by the Salt Lake City Stars. He returned to Salt Lake City once again on February 21, 2018, after his 10-day contract expired. Mitrou-Long left Salt Lake City once again for his second 10-day contract with the Utah Jazz, and returned to Salt Lake City after the second 10-day contract expired. He averaged 18.0 points, 6.1 rebounds, and 4.6 assists per game with Salt Lake City. In July 2019, Mitrou-Long joined the Cleveland Cavaliers for the 2019 NBA Summer League.
Indiana Pacers (2019–present)
On July 31, 2019, Mitrou-Long signed a two-way contract with the Indiana Pacers. On November 18, 2019, Mitrou-Long scored a career-high 12 points while getting three rebounds, three assists and one steal in a 115–86 win against the Brooklyn Nets. In the G League, he averaged 13.7 points, 6.1 assists and 5.9 rebounds per game.
NBA career statistics
Regular season
Personal life
Mitrou-Long was born on August 3, 1993, in Mississauga, Ontario, to Jersey Long and Georgia Mitrou. His father is of Trinidadian descent while his mother is a Greek Canadian. Mitrou-Long has three siblings and six half-siblings. His brother, Elijah Mitrou-Long, previously played college basketball for Mount St. Mary's University before transferring to the University of Texas in his junior year. After one year with the Longhorns, he transferred to the University of Nevada, Las Vegas. In summer 2015, Mitrou-Long decided to display his full last name on his jersey to honor his mother; up to that point his jersey had only his father's name on it.