Best short sports lens?

[Fitarane]

I see a lot of posts talking about the longer lenses, but what do people use as a short sports lens? Context: I'm the team (parent) photographer for my daughter's volleyball team, and usually have the freedom to walk the perimeter of the court during games. For the net play, I've had success using my 100mm f/2 but, for back row play, my kit struggles. I'm currently using a 50mm f1.8 and, as everyone can assume, AF speed is lacking. Is there a short lens that is popular with the sports shooters  https://getawaychief.com/lenses-for-sports-photography-nikon/ ?

Edited July 12, 2019 by Fitarane

[yukosteel]

I'd consider either XF 50-140mm F2.8 or learn how to master faster manual focus lens like 85mm F1.4 or 50mm F1.4