The former NBLer Matt Nielsen embarked on his coaching career in 2015. Nielsen was an assistant coach of Perth Wildcats from 2015 to 2019.

He then took on the assistant mentor role for the Austin Spurs for the 2019-2020 season and was later promoted to the head coach position.

As of 2021, Nielsen remains under Gregg as an assistant coach. Before venturing into the trainer role, Matt was a basketball player from Sydney.

He played for the Sydney Sky and Sydney Kings from 1995 to 2004 while he had gone undrafted at the 2000 NBA Draft. Likewise, he also played international basketball for many leagues around Greece, Moscow, and Spain.