Wilshere has been on the sidelines with a foot injury since March, but is expected to be included in Roy Hodgson's England squad for the tournament.
Oxlade-Chamberlain is also on the treatment table with a groin injury, but Wenger has insisted that it will not hamper the winger's chances of travelling with the team to Brazil.
"I think [Wilshere] will be completely safe and on that front medically alright," Wenger said in Friday's press conference. "At the moment [Oxlade-Chamberlain] has a an inflamed groin - for the World Cup he should be okay."
Both players will miss Sunday's match against West Bromwich Albion.