Maddie will wear full sleeves in combination with a short-sleeve under layer for cool mornings. As the day warms up, stripping off the sleeves is easy, and doesn't require a trip to the bathroom to remove the entire layer. Despite some arm issues in the past, I don't remember a full sleeve ever being recommended to her for medical reasons. She did wear a compression elbow brace/support a few times during her recovery, but it wasn't a full sleeve.
A couple of her teammates will wear one sleeve on occasion because they think it looks cool.
I could see a use for a compression sleeve to decrease any scrapes or gravel rash caused from diving in the infield.
Sarah Pauly is a rather accomplished pitcher, and she's seen wearing a compression sleeve on many of her demos here.
Im thinking about starting to wear compression sleeves. For me, it's more function over looks that I want to wear them (plus, I dont like the idea of wearing a long sleeve compression shirt in hot weather underneath my jersey. Did Maddie have problems with hers falling down when she was wearing them?
I don't think Sarah's elbow sleeve is what the OP was referring to? Maybe, but I was thinking of the longer (and usually a bit thinner material) version.
Sarah is wearing an elbow brace, (According to Rick, due to stress caused from the tens of thousands of curve's she's pitched over the years).