Without knowing how he performs in training, Mac deserves some starts, regardless of who it's in place of. I was using Moder as a comparison because he's has had a lot of opportunities this season and he's been ok, but could say the same thing about Gross and Lallana.
Mac's best role is...
What does Moder being a Polish international have to do with it? They had both played a similar amount of games in their native countries before moving here.
They're not like-for-like players but Mac has played in CM for us before and done well.
Imo, he has shown far more than Moder with much less game time.
He also is one of only a few players whose first instinct is to try and play forwards first, rather than backward.
I wouldn't blame him if he handed in a transfer request in January.