The duo could be selected to face Bulgaria after impressing for Manchester United at the start of this season.
Terry said: “The current crop that have come in have been great from the first day of training.
“Phil Jones has got a very good and very long future ahead of him. He made his debut against Chelsea and almost marked Didier Drogba out of the game at the time.
“He has got immense quality. He great in the air, quick, good on the ball with both feet but reads the game very well.
“But it’s not only him. Chris Smalling has been very impressive as well.”
Terry added: “Are they ready to start? I think so. You don’t go into the Manchester United side if you are not ready.
“They have shown some great individual and collective performances at United so they are ready.
“I don’t think age comes into it at all.
“You need to be given opportunities in life and if that comes around tomorrow they are certainly ready.
“If they are good enough, then they are old enough and all the young players believe in themselves.”