Mitchell has been in fantastic form this season, playing a direct role in 11 Premiership tries, which is more than any other player in the league.
He has scored four times and assisted a further seven, with only Harlequins No.9 Danny Care, with eight, setting up more scores in the league in 2021/22.
Mitchell was superb for Saints last Friday, setting up three scores in the bonus-point 36-20 success at Bristol Bears.
And the 24-year-old has earned a nomination for the Premiership's player of the month prize for November.
"Mitch is probably the best in the league at fixing that guy and putting his mate in," said Saints attack coach Vesty. "If you want someone in that place, it's him.
"He's done it for a long time and he had a special one last week.
"I do think he's maturing everywhere: on the pitch and off the pitch.
"It's really good to see and he's just such a good player."
Another talented youngster doing the business for Saints is Tommy Freeman.
The versatile back scored twice on his return to club action against Bristol.
And Vesty said: "He doesn't look like he's 20 years old - his frame is massive!
"Tommy's so cool and he just gets on with what he does.
"He's such a naturally gifted player.
"He's got vision, he's very good skills.
"He could be playing with his mates in the park and it would look very similar - and that's a really good thing for him. I wouldn't like him to ever lose that."