it's not necessarily an LDS exclusive issue - they just happen to take that particular comandment a little more seriously than most. it's the same commandment that prevented Sandy Koufax from pitching on Saturdays. If you know your Bible you'll remember the fate that awaited the man who was merely gathering sticks on the sabbath. It did not end well for him. But many in the LDS faith, for example Steve Young, Danny Ainge, Johnny Miller, Jack Morris, etc., etc. (there's probably hundreds of Mormons in pro sports) were and are able to work on Sundays without losing their membership rights.
So I would say that it's not the LDS faith that prevents them from playing on Sundays, it's their own consciences, after prayerful consideration, that prevents them from playing on Sundays.
So I would say that it's not the LDS faith that prevents them from playing on Sundays, it's their own consciences, after prayerful consideration, that prevents them from playing on Sundays.