PADDY McCartin's non-selection is more about other Saints performing well, rather than the 2014 No.1 draft pick's form being not good enough, says St Kilda coach Alan Richardson.

McCartin failed to earn a recall for the Saints' clash with North Melbourne, after being left out of last Saturday's 39-point win against Melbourne at Etihad Stadium.

After McCartin had played four successive games, Tim Membrey came into thside and kicked a career-best five goals against the Demons.

"It's not necessarily a form thing for Paddy, it's probably more a form thing for the guy that replaced Paddy," Richardson said at the club on Friday.

"He just hasn't been able to get back into a team that we were happy with, on the whole.

"That's OK, that's the life of a young player. You've just got to make sure you make the most of your opportunities."

McCartin will play for Sandringham in the VFL on Saturday evening, against Collingwood at the Holden Centre.

The 20-year-old is averaging a goal per game this season.

Richardson said honest communication was the key to managing McCartin's disappointment at failing to earn a recall.

"Paddy wants to play. He's a determined young man," Richardson said.

"As long as you're honest with them (young players), and give them real clarity around why or why not (they're playing), and there's a plan that's in place that they can understand and work towards, I'm not saying it's easy to cop, but it's understandable.

"He knows where he sits."

Meanwhile, the Saints are awaiting final confirmation from in-form skipper Nick Riewoldt that he intends to play on in 2017.

Riewoldt, who has spent plenty of time on the wing this season, is ranked first in the competition for average marks and has 15 goals from six games in 2016. 

"His own performance has been really strong," Richardson said.

"There's a lot of boxes that he's already ticked and it's probably really close that he'll make the ultimate call.

"We'd like him to continue to play." 

The 33-year-old was drafted at No.1 in 2000 and brought up his 300th game against the Western Bulldogs in round two.