Hales has been in impressive form for Nottinghamshire this season, and Bopara believes that he is one of a number of players, including the likes of Jason Roy, Jonny Bairstow, James Taylor and James Vince, who are knocking on the door.
"I've always been impressed with Alex Hales," the 29-year-old told reporters. "He's a brilliant batsman.
"Every player in that top six has a chance of being in the World Cup squad. Those players can dominate an attack."
Hales has played 32 times in Twenty20 cricket for England, but has not yet been capped in one-day internationals.