Mindful of the extraordinary interest that Armstrong's comeback has generated, race organisers want to avoid a crush at the airport when he touches down.

Armstrong's Astana team are scheduled to arrive in Adelaide on Sunday morning and the seven-time Tour de France champion is apparently not expected until next week.

Belgian team Silence-Lotto arrived in Adelaide early this morning.

The only member of the seven-man team not with them is Australian Matt Lloyd, who will defend his national road race title on Sunday at Buninyong, near Ballarat.

Silence-Lotto star Cadel Evans, second at the last two Tours de France, will again not race the Tour Down Under.

Evans is focussing on his preparations for July's Tour de France.

Armstrong also hopes to race at the Tour de France, which he last won in 2005, but his comeback after a three-year break from top-level cycling means he is on a different schedule to Evans.

Armstrong, 37, is training on Hawaii's Big Island before heading to Adelaide.

It is understood he arrived there three days after Christmas.

His training rides have included the Queen K highway, a stretch of road made famous by the Hawaiian Ironman triathlon world championships.

The Queen K is surrounded by lava fields and it is a barren landscape, usually brutally-hot and often featuring blustery trade winds.

Given that the temperature at the Tour Down Under can rise to over 40 degrees, it is the perfect pre-race preparation for Armstrong.

His long-time training adviser, Chris Carmichael, has visited Armstrong in Hawaii and told Italian newspaper La Gazzetta dello Sport that the star cyclist's form is encouraging.

"The progress I am observing is equal to what he had before retiring," Carmichael said.

"At first he thought he would not be in acceptable form for the first races.

"He will continue to train in Australia because he is still at the start of the road leading to the Tour de France."

One of the greatest unknowns of Armstrong's trip to Adelaide will be his racing form at the Tour Down Under.

He is highly unlikely to challenge for the overall win in the January 20-25 race, but could well light up the event with a big attack during one of the stages.