Just over five months remain until Hodgson has to select his 23-man party for the tournament in Brazil, and the England manager says every place in the squad is up for grabs.
That will be welcome news for Barkley, who forced his way into the last England squad for their last six games, but has only made three substitute appearances.
The Everton midfielder, 20, boosted his chances of a World Cup call-up with a stunning free-kick against Swansea last week while Morrison has been one of the few to impress at West Ham this season.
Hodgson would not have a problem selecting either player in his squad, so long as they play regularly and impress in the new year.
"What they have to do - those two players - is realise that we do have great faith in them," the England manager told BBC Radio 5 Live's Sportsweek programme.
"We do have enormous admiration for their talent and we believe that they are going to be exceptional players.
"What they have got to do is keep performing week in and week out and they have got to make certain that they are that team sheet every week keeping more experienced players out of the team.
"If they continue to do that then come May their names will be in serious discussion with us as well."
Sir Alex Ferguson sold Morrison to West Ham after a number of disciplinary issues, but the midfielder has found his feet in east London following a loan spell at Birmingham.
The 20-year-old, who has scored five goals this term, is yet to receive a full international call-up, though, and he only played his first Under-21 game in October.
Morrison and Barkley are not the only two contenders to gatecrash the World Cup squad in the same way that a teenage Theo Walcott did in 2006, however.
"I think it's unfair just to mention those two," Hodgson added.
"You can't ignore the likes of Raheem Sterling, whom I saw play quite brilliantly play for Liverpool the other day.
"There's Nathan Redmond at Norwich and you can't forget (Manchester United forward) Wilfried Zaha."
Hodgson has one more friendly - against Denmark in March - before he names his provisional 30-man World Cup squad on May 13.
The final 23-man squad will be announced 10 days before the start of the tournament on June 2.