There is many takes to this, meaning each of the lenses work great, but have different strengths, benefits and challanges.
The quick answer is 50 or 35mm, at rather closed aperture, like F8, to have a wide depth of field. Moving subjects can be difficult to get in proper focus, so unless you have very good experience with manual focus it will be difficult or impossible to get a sharp photo at wide open apertures. Keep an eye on shutter speed though, to freeze action you probably want it to be at 1/500 (or 1/250 or 1/1000, depending on the speed of the action). Make sure you have plenty of light for your first tries, to facilitate high shutter speeds at narrow apertures.
A wider lens makes it easier to keep the moving subject in the frame, thus 35mm has a benefit there. Assuming you stand a bit away from the action the 50mm might be a better fit. But you will have to find out what fits best to your style of photography.
Maybe first try with your digital camera: exposures have no cost there, and you can view the results on the same day on the computer, or even immediatley on the screen of the camera. Thus any errors will show up quickly, and you can learn from them since you still remember exactly how you shot the respective photo. Also the EXIF data contains shutter speed, aperture etc., so you can understand what effected the photo. Photographing sports can be quite demanding, and for starting with it using film can be frustrating and expansive.
If your digital camera has interchangeable lenses, it would be a fun option to get a cheap adapter for your wonderful Rokkor lenses - in principle that works for any camera, DSLRs can be tricky as most mounts are longer than the old Minolta mount. It will work well on any mirrorless camera though! This is great to learn the usage of the vintage lenses, and also can be a great artistic choice - some pro photographers use a similar setup because of the beautiful rendering of old lenses (famous recent example is the use of very affordable lenses like Helios 44-2 for filming Dune II).
Another approach would be to simply use your digital camera as is, and checking on what focal length you find most suitable for you. Mind that there might be a 'crop factor' between your digital camera and the Minolta SLR, which is 'full frame'.
In any way, don't hesitate to try things out, and have fun with those wonderful vintage lenses and cameras!