Nathen - if we assume that the matrices are of the same dimension (which they will be for this game) then you can use the position of the player in the game matrix (given by row and column indices) to determine if there is a mine in that same position. For example,
playerRowIndex = 4;
playerColIndex = 5;
isMine = mine(playerRowIndex, playerColIndex);
where isMine will tell you if there is a mine where the player is. I think from what you have posted elsewhere you will have this position and in the game matrix, you'll set this to 100 (indicating position of player).