The 21-year old midfielder landed in Paisley at the beginning of the year and is single-minded in furthering his development so he has every chance of forcing his way into the Magpies first team upon his return.
"I haven't spoken to Alan Pardew or anybody at Newcastle about what happens at the end of the season," Newton told the Daily Record.
"They have brought in a lot of new players but I can't worry about that. I just have to look after myself and keep improving through playing for St Mirren.
"If I go back and Newcastle say I'm good enough, that will be great but only I can make that happen."
And on the standard of the Scottish Premier League, which at time gets a bad rap, Newton added: "Paul Dummett is here with me from Newcastle and St Johnstone have just signed my teammate Mehdi Abeid on loan, so somebody at St James' Park must recognise this is a good level or they wouldn't be allowing us to come up here and play."