But the team will take experienced Australian rider Graeme Brown in what will be his 14th edition of the race.
Reflecting on a solid eight year career which began with Drapac/Porsche in 2007, Lapthorne said he leaves professional cycling with many memories.
“One of the best memories I have was my first taste of racing in Europe when I was 23 in 2007 and current Australian road champion with Drapac, Lapthorne said.
"We were a close bunch of mates traveling and taking in the experience of racing some tough tours like Tour of Austria and Brescia along with racing some pro kermesses in Belgium along the way.
“Michael Drapac, team owner has always been committed and provided me with the opportunity to race at the highest level. Drapac Professional Cycling has been a major part of my life and I will always be thankful for his belief in me. These years of riding in red for Drapac will always be memorable ones.
“No matter what I do in the future I’ll always give my all and do the best job I’m capable of just like I did in cycling. I can look back and say I rode with integrity and respect, and will always strive to do the same in the future in any role I do. I would love to stay involved with the sport so we will see in the year ahead.
“Thank you to my teammates over the years, my sporting directors and my wife and family. Cycling is full of passion, emotion, it can be brutal but beautiful which I love and what life is about.”
For now though, the focus for the Drapac team after the Nationals is the 2016 Santos Tour Down Under. Lining up for its third straight year as a wildcard entrant, Drapac General Manager Jonathan Breekveldt said the squad aims to produce similar results to 2015.
“The team left the race in 2015 with the best possible result, winning the final stage and we will go back again to have a similar impact,” he said.
“It is also a special occasion for Graeme as it is his 14th TDU and we are excited to help him commemorate this feat over the course of the week.”
The two-time Olympic gold medallist and three time Santos Tour Down Under stage winner Graeme Brown said there is nothing like the Tour Down Under.
“This race is very special to me. It is such a great atmosphere, and the spectators are sensational, with fans lining the roadside for most of every stage,” he said.
“I am looking forward to my 14th start at this event and the course for this year’s race looks to set up an action packed event.”