Maine Red Claws (2016–2017) On June 24, 2016, Nader was drafted by the
Boston Celtics with the 58th overall pick in the
2016 NBA draft. He then joined the Celtics for the
2016 NBA Summer League. On October 31, 2016, he was acquired by the
Maine Red Claws of the
NBA Development League. On April 14, 2017, he was named the 2016–17
NBA Development League Rookie of the Year, becoming the first internationally born player to be named NBA D-League Rookie of the Year and the third Red Claws player to earn the honor. Nader averaged 21.3 points, 6.2 rebounds and 3.9 assists in 40 games, propelling the Red Claws to a 29–21 record and the Eastern Conference's second seed in the 2017 NBA D-League Playoffs. In addition to shooting 44.6 percent from the floor, Nader recorded a team-high 99 three-pointers. He also tallied 16 points, four rebounds and four assists during the 2017 D-League All-Star Game in
New Orleans.
Boston Celtics (2017–2018) On July 14, 2017, Nader agreed to a 4-year, $6M deal with the Celtics. He made his NBA debut on October 18 against the
Milwaukee Bucks. During his rookie season, he received multiple assignments to the Maine Red Claws. In four games with the Red Claws, he averaged 21.3 points, 5.8 rebounds, and 1.5 assists per game. Nader posted 3.1 points and 1.4 rebounds per game with the Celtics, and appeared in 11 playoff games during Celtics Eastern Conference Finals run.
Oklahoma City Thunder (2018–2020) On July 23, 2018, Nader was traded to the
Oklahoma City Thunder in exchange for
Rodney Purvis. Oklahoma City also received cash considerations in the deal. On November 28, 2019, Nader scored his career-high 23 points with two rebounds in a 136–119 loss against the
Portland Trail Blazers.
Phoenix Suns (2020–2022) On November 16, 2020, the Thunder traded Nader and
Chris Paul to the
Phoenix Suns for
Kelly Oubre Jr.,
Ricky Rubio,
Ty Jerome,
Jalen Lecque, and a protected 2022 first-round pick. After getting a
concussion in a December 2020 preseason against the
Utah Jazz, he made his season debut on January 11, 2021, against the
Washington Wizards. On January 28, Nader scored a season-high 16 points in a blowout 114–93 win over the
Golden State Warriors. On March 4, he had a near-double-double performance with 14 points and a career-high 9 rebounds off the bench in another blowout victory over Golden State, this time ending with a 120–98 win. Nader made the
NBA Finals, but the Suns lost in 6 games to the
Milwaukee Bucks. On August 6, 2021, Nader re-signed with the Suns. Nader was then later waived on February 10, 2022.
S.E. Melbourne Phoenix (2023–2024) On December 12, 2023, Nader signed with the
South East Melbourne Phoenix of the Australian
National Basketball League (NBL) for the rest of the
2023–24 season. == International career ==