Austin Spurs (2015–2016) After going undrafted in the
2015 NBA draft, Washburn joined the
Golden State Warriors for the
2015 NBA Summer League. On October 22, 2015, he signed with the
San Antonio Spurs, but was waived just two days later. On October 30, he was acquired by the
Austin Spurs of the
NBA Development League as an affiliate player of San Antonio.
Tigers Tübingen (2016–2017) After joining the
Los Angeles Clippers and the
San Antonio Spurs for the
2016 NBA Summer League, Washburn signed with
Tigers Tübingen of the German
Basketball Bundesliga on August 5, 2016.
Second stint at Austin Spurs (2017–2018) On November 2, 2017, Washburn was included in the 2017–18 opening night roster for
Austin Spurs. In April 2018, he helped Austin win the
NBA G League championship.
Canterbury Rams (2018) On April 17, 2018, Washburn signed with the
Canterbury Rams for the
2018 New Zealand NBL season.
Third stint at Austin Spurs (2018–2019) On September 18, 2018, Washburn signed an Exhibit 10 deal with the
San Antonio Spurs, but was waived three days later. On October 22, 2018, Washburn was included in the training camp roster of the
Austin Spurs.
Memphis Grizzlies (2019) On January 15, 2019, Washburn signed a
two-way contract with the
Memphis Grizzlies, a deal that saw him split his time between the Grizzlies and the
Memphis Hustle of the
NBA G League. On April 10 he scored a career high 8 points against the
Golden State Warriors.
Delaware Blue Coats (2019–2020) On July 7, 2019, Washburn was traded to the
Golden State Warriors in exchange for
Andre Iguodala and a protected first-round draft pick. The Warriors also received a
traded player exception in the deal. He was waived on July 17, 2019. He was named to the training camp roster of the
Delaware Blue Coats, which acquired his returning players rights from the Austin Spurs. Washburn averaged 6.5 points and 4.8 rebounds per game.
Return to Delaware (2021) On January 14, 2021, Washburn re-signed with the
Delaware Blue Coats where he averaged 7.9 points, 2.6 rebounds and 1.4 assists on 42 and 36 per cent shooting from field goal and three-point range, respectively.
London Lions (2021–2022) On June 11, 2021, Washburn signed with the
Fraser Valley Bandits of the
Canadian Elite Basketball League,
Fourth stint at Austin (2023–2024) On November 20, 2023, Washburn joined the
Austin Spurs of the
NBA G League. However, he was waived on November 4, 2024. ==Career statistics==