skipping over zeros when calculating standard deviation & average

I have a list of player data from the NBA. Every day I import the previous days game stats. So for example, I have a players data of the last 10 games played. I then calculate the rolling average minutes played of the last 10 games, and the rolling standard deviation of minutes played of the last 10 games. When a player sits out a game, I do not want that zero value to count against the average or standard deviation. So how can I skip over these values when computing my data?

also, now that I am thinking about it, to keep my rolling data of last 10 games true, if there is a zero in the data i would need to go back 11 games.