On December 18, 2010, following a nine-game suspension Selby joined the 2010–11 Jayhawks, scoring 21 points in 27 minutes and making 5 of 8 three-point shots. While Selby sat out, Kansas led the country in many team statistical categories. As a result of his suspension and later injuries Selby played in only 26 of the teams 38 games and averaged only 14 minutes per game after returning from injury. For the season he averaged 7.9 points and 2.2 assists on 20.4 minutes per game.
Controversy
After choosing to attend Kansas, a report came out stating that Selby had not yet been cleared to play by the NCAA. According to this report, the NCAA had been investigating for months the relationship between Selby and Robert "Bay" Frazier, the business manager for New York Knicks star Carmelo Anthony. Selby had acknowledged a friendship with Anthony in past interviews and spoke of his contact with Frazier in an April story in The New York Times. All three are Baltimore natives. Maeshon Witherspoon, Selby's mother, told The Times that she had known Bay since elementary school and had asked him to serve the role of an adviser during his college recruitment. The Times report said Witherspoon asked Frazier to host Selby's in-home visits with college coaches at his own home and that Frazier attended a KU–Missouri game at Allen Fieldhouse in January 2009. On November 21, 2010, the NCAA made their final ruling on the matter, suspending Selby for nine games, and ordering him to pay $4,607.58, the total of the "improper benefits" received from Frazier, to the charity of his choice.
Professional career
On April 14, 2011 Selby announced via Twitter that he would enter his name in the 2011 NBA draft. On June 23, 2011 Selby was selected as the 49th pick in the 2011 NBA draft by the Memphis Grizzlies, joining other former University of Kansas players Xavier Henry and Darrell Arthur on the Grizzlies roster. On December 10, 2011, Selby signed a contract with the Memphis Grizzlies. He was assigned to the Reno Bighorns on February 12, 2012. In the 2012 NBA Summer League, Selby earned co-MVP honors with Damian Lillard. Selby was reassigned to the Reno Bighorns on December 17, 2012. He was recalled on December 22, 2012. On January 22, 2013, Selby was traded along with Marreese Speights, Wayne Ellington and a future first-round draft pick to the Cleveland Cavaliers in exchange for Jon Leuer. The Cavaliers assigned Selby to the Canton Charge of the Development League on January 24, 2013. On March 3, 2013, Selby was waived by the Cavaliers. On March 7, 2013, he was acquired by the Maine Red Claws. In September 2013, he signed with the Qingdao Eagles of China. On November 16, 2013, he was waived by the Eagles. On January 7, 2014, he signed with Cedevita Zagreb of Croatia. On February 5, 2014, he parted ways with Cedevita. In August 2014, he signed a one-year deal with Bnei Herzliya of the Israeli Basketball Premier League. In November 2015, he signed with Socar Petkim of the Turkish Basketball Second League. In August 2016, he signed with Best Balıkesir of the Turkish Basketball Super League. However, he left the club two months later before appearing in an official game for them. On January 12, 2017, he signed with Israeli club Maccabi Kiryat Gat. Later in 2017, Selby signed to play for the Incheon Elephants of the Korean Basketball League: he played 36 games during the 2017–18 KBL season, averaging 17.4 points, 3.4 rebounds and 3.9 assists in 25.7 minutes of playing time. In 2018 he signed for Ferro Carril Oeste of the ArgentineLiga Nacional de Básquet, playing 1 game and scoring 12 points in 16 minutes. On June 23, 2020, Selby signed with Kumanovo of the Macedonian First League.