Really torn on a solid lens for softball

[FLHX2k8]

I am currently shooting a Nikon D750, and a Tamron 70-200 2.8 VC. It worked great for my daughters basketball games, but im having to "crop to zoom" a lot more than id like for her softball photos. I can get great shots when shes batting, and i can position myself on the 3rd base line when shes running from 2nd to 3rd. But other than that, im very limited. I'm considering the Nikon 70-300 4.5-5.6 VRII. I know its a variable aperture lens, and limited during bad lighting. But im curious how much success other people have had using this lens for daytime outdoor sports. A 300 2.8 isnt in my budget, and this is the next best thing I can find. Thanks in advance for the help.

 

[tirediron]

How about the 300mm f4? Only one stop different than the 2.8 and much, much less expensive!