This isn’t exactly what you asked for, but I think it is an easier and problably better solution. I do a lot of recruiting videos and the college coaches I talk to want to see footage that has had very little done to it (slow motion, freeze frame, music, etc.) What I have done is to identify the player at the beginning of the play and then have the effect quickly fade away so the coaches can see the whole field and other players without obstructions or being grayed out. The easiest way to do this in Premiere Pro is to open the title designer and type an ‘O’ or ‘[ ]’ or other character that you would like. You can make it any font or color that will help it stand out against the background. Place this ‘title’ over the footage and use the motion controls to size and place it over your son as the play starts. You can move the character with the motion controls to follow your son’s motion. After a second or two fade the title away.
Good luck with the recruiting video. I hope it helps your son get into the program that he would like.