Clarke-Salter is captaining England Under-21s at the European Under-21 Championship and O'Hara says it is a good time for him to impress.
“I think [Chelsea are] going to have to look at that [using Clarke-Salter]," O'Hara said.
“They're going to have the transfer embargo, new manager coming in.
“They're going to have to use their youth players and they've got a fantastic set up in terms of players they've had out on loan. They've got experience now, the Chelsea players that have gone out.
“I think he will be looking to push on, if he has a good tournament people are going to be watching him.
“The club will be watching and the national side so it's important he has a good tournament, shows leadership skills.
“I think he'll be a big part of Chelsea."