bald spot on cat?

Samson is a Maine Coon and gets lots of mats in his fur that we have to remove.
Today we noticed a large bald spot behind his ear (one place he often gets knots). It's quite bald and large (1-2 inches?).
Is it possible that tugging on knots in that area damaged the rest of the hair follicles and the hair fell out and it just has to grow back now?
My husband pointed out something similar on his chest (where he also gets a lot of mats) and it looks like it's started to grow back there.
We haven't noticed him scratching behind his ear or anything.
Anyone had this?
We'll keep an eye on it and maybe talk to our vet about it.

is the spot totally bare? is there any redness or inflammation? with a longer-haired cat it is certainly possible he yanked out a tuft of fur, leaving a bald spot. or it could be ringworm or another malady. keep an eye on it and if the fur doesn't start growing back fast consider a vet visit.

No redness, scaliness or anything.
Just looks like a clean little bald spot.
Like someone shaved a circle behind his ear : (
It's not in a place that cat could really groom on his own.
We'll keep an eye on it....

The only bald spots we've had any experience with were 1) when Chumley was overgrooming because he was all itchy from allergies, and 2) when Spooky was overgrooming because she was stressed.

But this sure doesn't sound like either one of those.

it was just a knot he pulled out!