The duo has impressed for Villa this season and O’Neill believes they deserve to be a part of England’s World Cup squad.
“I’ve said this before, surely there must be places up for grabs that the England manager is not completely decided upon,” O’Neill told the Birmingham Mail.
“Stephen has been hovering around the squad just recently and that’s good news and Stewart, of course, has been out with injury but I think Capello thought a lot of him beforehand anyway. All of those things will encourage them.”
“I think there’s a lot more to come from him,” he said of Downing.
“Again, he’s had no pre-season, he’s just been thrust into it and played a lot of games in succession.
“He hasn’t really had a break either. I’ve been really pleased with him. I think he’s slotted in very nicely.
“He’s got great delivery and I think he has demonstrated in periods of games here the ability to go past people to leave them for dead.
“I think that’s the sort of thing that he can do and that will become more prevalent as he gets to grips with it all.”