[13][14] In his debut for United on 9 October 2015 in the team's season opener, Blanchfield scored a career-high 29 points with seven 3-pointers in a 99–84 win over the Crocodiles.

[15] He went on to help United earn the minor premiership after finishing the regular season in first place with an 18–10 record.

On 16 October 2016, in United's fourth game of the 2016–17 season, Blanchfield hit eight 3-pointers and scored 27 points on 9-of-11 shooting in a 95–83 win over the Illawarra Hawks.

In his lone season with Sydney, Blanchfield averaged 9.1 points and 4.0 rebounds per game on 33.3% shooting from beyond the arc.

[28][29] In game one of the Wildcats' semi-final series against the Illawarra Hawks on 10 June 2021, they lost 74–72 despite a game-high 24 points from Blanchfield.

[34] In game one of the grand final series against Melbourne United, the Wildcats lost 73–70 despite a game-high 27 points from Blanchfield.

[37][38][39][40] On 21 September 2021, Blanchfield was sidelined for three to four months after undergoing surgery to repair damaged cartilage in his left knee.

[49] On 28 June 2023, Blanchfield signed a two-year deal with the Illawarra Hawks, returning to the franchise for a second stint.

[51] In 2007, Blanchfield played his first season with the Mackay Meteors in QBL, where he was a valuable member of the team despite being just 15 years old.

[56] With the Heat in 2012, he earned QBL All-League Team honours for the second straight year[56] after averaging 19.7 points, 7.4 rebounds, 1.8 assists and 1.8 steals in 13 games.

[63][64] He later earned NBL Player of the Week honours for round eight[65] and led the Sharks to victory in the grand final with a game-high 23 points and 14 rebounds in a 72–68 win over the Wellington Saints.

[68][69] In 2018, Blanchfield returned to the Meteors[70] and averaged 21 points, 10 rebounds and 4.3 assists on 47% shooting, which saw him voted league MVP and a member of the QBL All-League Team.

[71][72] On 18 March 2019, Blanchfield signed with the Southland Sharks for the 2019 New Zealand NBL season, returning to the team for a second stint.

Blanchfield was set to play for the Rockhampton Rockets in the NBL1 North in 2020,[74] but the season was cancelled due to the COVID-19 pandemic.

[3] He helped the Emus defeat the United States to claim bronze at the Albert Schweitzer Tournament in Germany.

[84] In 2013, he played for Australia at the Stanković Cup[85] and the World University Games,[86] where he won gold and silver respectively.

[90] In April 2023, Blanchfield helped the Australia 3x3 team win silver at the FIBA 3x3 Asia Cup.