I have knitting sq I want to use up. I also have blue jean mat and fleese.

I want to do nine patch with knitting and BJ mat and use fleese for backing with no batting. Will this work? and do I need to sew something on the back of the knitting? Thank you in advance for your help.

The knitted blocks will stretch, you could sew a cotton fabric to them to help stabilize the blocks. I don't know if an iron on stabilizer would work for this or not...
The knitted blocks could be sewn on a square, leaving a border of the fabric around them, and you could sew the border area to the denim.
As to trying to quilt this? I may consider tying instead.
I think this is a very creative idea :D:D:D

Thank you for the input. I thought I would surge squares, I will post how it works when I get started.