The game I moderate (Operation Neptune) has entry when submitting for the number of players and which player the submitter is. However, the game is only ever 1 player and it's redundant. 

I know other games don't have that in their submission pages so I wanted to see how I could remove it.

As moderator of the leaderboard, you are able to submit runs from other users. That's why you (as moderator) can see the input field 'You are ...'. I can confirm this input field doesn't show up as a regular user submitting a run to the leaderboard. Instead, it will automatically fill in your name without the extra input field showing 'You are: Player 1'.