Chris Bascombe said at the start of the season, that all a gk has to do for Liverpool, is do very little very well. He had 2 saves to make last weekend, and made them. He had to come out to win the second one cleanly. Without them, Divock can't win the game.
When his rival for his national team spot had to race out and win the ball cleanly recently, he took the forward down not once but twice, and conceded 2 penalties.
The forwards get all the attention and adulation, but without Alisson we don't win the games we should win and we wouldn't be hunting City down. 9 clean sheets so far in 14 games is about as close to waterproof as you can get.