You can contact all members of any team by clicking "Email the Team" on the far right edge of the respective team in the Teams listing (smartphone users may need to rotate their phone to see the full width).  Useful if you need to let the opposition know your team cannot make a game?

Any member can add themselves to a Spares list, and/or the Free-Agent list.  Folks looking to pick up a player can look in the Free-Agent Listing.