The 23-year old from New Zealand's Football Championship will join Australian and New Zealand-based players at the 12-day All Whites camp on April 28 and head coach Ricki Herbert says he has a real chance of being selected for the World Cup squad.
"Aaron's a player we've been monitoring and I invited him in for a couple of weeks recently with the (Wellington) Phoenix," Herbert said.
"Assistant coach Brian Turner saw Aaron play again on the weekend and he's been able to make a difference as far as Canterbury making the finals is concerned.
"In the big games against Auckland and Waitakere this season he's stepped up and performed.
"Now is a good chance to bring him in with players like (Tim) Brown and (Leo) Bertos and see what his work is like at that level."
Clapham joins 14 other New Zealand hopefuls at the training camp in Auckland which will run from April 28 until May 10.
The other players are:
James Bannatyne, Glen Moss, Mark Paston
Tony Lochhead, Dave Mulligan, Ben Sigmund, Ivan Vicelich
Costa Barbarouses, Shane Smeltz