I recently saw a guy working a college baseball game wearing a CP that was the slimmest I've ever seen. I approached him afterwards and asked: it was a Pro Nine, it was pretty slim and small, and he had removed the shoulder caps. It comes in three sizes (12" the smallest) and is only ~$50 here:
https://baseball.epicsports.com/prod...rotectors.html
The copy says good for "all levels of professional minor league baseball and college baseball and
fastpitch."