One of Caleb Ewan's main assets – his small size – could be one of his biggest handicaps when he bumps shoulders with the big boys in the pack in Europe.

Ewan has been warned to expect rough times when he returns to Europe from the Tour Down Under, with fellow Australian Mark Renshaw tipping big German sprinters such as Andre Greipel and Marcel Kittel – and their teams – to use their greater size and physicality to counter the diminutive flyer's lightening speed.

Renshaw (Dimension data) believes that while the size of 21-year-old Ewan (Orica-GreenEDGE) "is certainly an advantage" because of the low and flat position he can reach, "it is also a little bit of a disadvantage for him.

"He will be easier to move [out of the way]. Little guys will be easier to move. If he comes up against a good Kittel or Greipel … he's a lot smaller [than them]."