Any goalie that allows many goals to be scored by an opposing team, thus causing his team own team to lose the game.
Although team St. Amour’s offence was rather weak, it was ultimately their sieve like goaltender that allowed the opposing team to show them "Who's Boss"
is very commonly used metaphorically to describe things that are leaking or something that has holes in it.
1) leaks like a sieve
2) bad defense in sports (i.e. poor goalie in hockey)
2) That goalie sucks. He is about as porous as a sieve