His season with Discovery Channel featured some impressive rides but was interrupted by injury and eventually ended when he resigned after an incident in a Christchurch bar.

He attempted to relaunch his professional road career in the US when he signed for Continental Pro team Health Net–Maxxis and began strongly with two top ten stage finishes in the Tour of California beating many big name ProTour regulars.

Unfortunately for Roulston his first year at HealthNet ended when a medical examination revealed irregular heart activity and he was advised to stop riding immediately.

In the 2009 Tour of California, Roulston began a perfectly executed lead out to allow team sprinter Thor Hushovd to win Stage 3.

[14] Hayden Roulston spent his last few seasons riding as a key domestique for Fabian Cancellara at Trek Factory Racing.

[15][16][17][18] In October 2015 Roulston announced his retirement from road racing, having previously revealed that he would make a return to the track with a view to competing in the team pursuit at the 2016 Summer Olympics.

[19] Hayden Roulston competed in March 2016 in Le Race with the intent of obtaining a "good, intensive training ride".

[20] He won the 100 kilometre race from Cathedral Square in Christchurch to Akaroa dominating in the cross winds and forcing the pace on the climb to Hilltop.