[citation needed] Debuting in 1998 Wesser moved from his hometown of Rockhampton to the foot of the Blue Mountains, New South Wales, to play for the Penrith Panthers but he found trouble in pushing for a first-grade spot with Peter Jorgensen holding that title.

In 2002, he scored a Penrith club record of nineteen tries, including three hat-tricks, and was dubbed "Rhys-Lightning" and soon became a crowd favourite with his acceleration and line-breaking ability.

The Panthers won their second premiership title, beat the Sydney Roosters in the 2003 NRL grand final in which Wesser played at fullback.

[citation needed] As 2003 NRL premiers, the Penrith travelled to England to face 2003 Super League champions, the Bradford Bulls in the 2004 World Club Challenge.

Wesser made the Aboriginal selection in the exhibition game against the New Zealand Māori side as part of the official opening of the 2008 World Cup on 26 October.