sigma 120-300

Bear with me. I am a VERY amateur photographer. I like taking photos at football matches. All the numbers and language when it comes to camera equipment is like listening to mountain bikers talking about their equipment! I have a Nikon D3100. Old I know, but it works. I bought it new about 13-14...

My next purchase is going to be a 300mm 2.8, but I'm not sure what to choose. I shoot with a Canon 7D MkII and have a 70-200 2.8 and mostly shoot football mostly Womens and Non-League and looking for a lens to maybe to use in years to come shooting higher level football. I have used the Sigma...