Here what you do in drills out do him.lets say you guys run the 40 yard dash and he runs it in 4.3 you run it in 4.2 outdo him push your self harder . bE better push harder work harder . GOOD LUCK
So you've got to prove to the coach that you deserve to keep your place.
Believe in yourself - go out and prove you are a better prop than he is. Push yourself harder than he does, and don't leave anything left in the tank. Whether it be a drill, a fitness test it doesn't matter, give everything you have got, and prove that you are a better prop than he is, and are worthy of a plave in the first team. I play rugby league, but the principles are exactly the same. Involve yourself on the game as much as possible, make more carries than he does, more tackles than he does, and if you work hard off the field, you will be successful on it. If you need a bit I advice, tell me, and I will send you an email. All the best mate.