Let me start by saying this tree looks completely healthy and has about 9 great big lemons on it. Foliage looks great other than a few CLM.
HOwever, I just happened to notice the base of the tree had a couple of bad looking spots.

If you can tell from my pictures, please advise. I am hoping its nothing. I really can't remember if it was like this before. Never noticed it.

is there any chance that some mechanical trauma occurred to the tree? like a lawnmower bumped against the tree or a weed-eater used around it?

looks to me like old wounds that are healing. my guess is it is fine.

It does look like its healing. I tend to lean towards your assessment and I sure hope that is the case. Maybe the lawn guy smacked it early on.

Thank you!

Sure looks like mechanical damage, probably lawnmower.