Marriott, 19, is heading out on loan to Carlisle United in League Two, while Nouble, 22, is available for permanent transfer or loan.
Speaking of Nouble, McCarthy told the Tractor Boys' website: "We've got four strikers now. He's seen other players come in and he's not daft. He wants to play games. He wants to play in someone's first-team, not sit on the bench.
"He's worked hard for us and hopefully he can get fixed up with another club."
McCarthy also revealed that free agent midfielder Jack Collison has been training with the club and could join after his release by West Ham United.