Straigten images VERTICALLY with the crop tool?

Hello!
I work on high school sports photography, as a photo retoucher/artist. Often we shoot individuals and large groups inside gyms, usually at an angle to a wall instead of straight-on, for a more interesting background.  Each photo is angled slightly differently, because the photographer is hand-holding while he deals with the rest of the craziness that is high school team photography = 20+ unsupervised high school athletes. Often, the only way I can straigten the photo is by making sure that vertical lines in backgrounds, fences, and anything else that's reliably vertical, vertical. Horizontal straightening during cropping doesn't help when there are no truly horizontal lines. And because they don't shoot on a tripod, the angle isn't consistent enough for an action.

Is there a way to change the horizontal straightening tool to a vertical one? I don't think so, and it doesn't seem to be a common problem from what I can see on this forum. I just want to be sure that I'm not overlooking an obvious fix.

Thanks!