Speaking to BBC Radio Northampton, Thornton who helped the Cobblers win through in the last round against Reading said: "You always dream of playing in the Premier League, against those players.
"We're not expected to beat them so we've got to enjoy it. If we get the ball down and play, we're a good team.
"The manager wants me to play higher up the field, as that's where he thinks I'm dangerous," Thornton, who has also played for Brighton on loan and Nuneaton Town went on to say.
"I'm just concentrating on staying in the team, and trying to do well for myself and the team."