The tracksuit is a garment which protects from spills and swills with its unique wine wicking abilities, while being comfortable and breathable for everyday wear.
There are lots of other substances that are much better at wicking moisture, like the little silica packets that say “Do Not Eat” on them, or even cat litter.
Players would've likely worn a simple cotton bra without an underwire, which would've been the most comfortable and easy to wash, but not necessarily the best for wicking sweat and moisture.
Zooming in revealed that the papillae have a U-shaped cavity at their tips, which has a wicking effect and helps carry droplets of saliva through that top layer of fur down to the cat's skin.