Some impressive performances in an under-performing Otago side brought him to the attention of Dunedin-based Super Rugby franchise, the who named him as a member of their wider training group for the 2015 Super Rugby season. 2015 was to prove to be a memorable year for the Highlanders who lifted the Super Rugby title for the first time in their history, while for Walden, the presence of midfield backs such as Malakai Fekitoa, Richard Buckman, Jason Emery and Shaun Treeby meant he had to spend the year kicking his heels on the sidelines. His Super Rugby debut came the following year in week 1 of the competition, a 33-31 defeat away to the Blues. Overall he scored one try in 6 matches while still a wider training group member in 2016 and new Highlanders head coach, Tony Brown saw fit to promote him to the full squad for 2017.