Alisson has been one of the side's most consistent performers for Jurgen Klopp since he arrived for £65m from Roma in 2018.
He has helped the club win four trophies - including the Champions League and Premier League - and many believe he's the best goalkeeper in the world.
Nevertheless, Premier League icon Di Canio insists Alisson is not always faultless and believes he could cost his side against the Serie A champions if he has an off day.
"Alisson performs heroics in goal, but every four or five games he has a bit of a howler," the West Ham legend told Sky Sports Italia.
"Liverpool have weak points, every team does."
Inter coach Simone Inzaghi is not concerned by his side's dip in form heading into their Champions League last-16 tie against Liverpool.
The defending Serie A champions have picked up just one point in their last two matches after a defeat to city rivals AC and last weekend's draw at Napoli.
Jurgen Klopp's side, by comparison, have lost just once since November and are on a six-match winning run.
"We knew it would be a busy period for us. I am very happy with the performances," said Inzaghi.
"Against Milan we were excellent for the first 70 minutes, against Napoli we were excellent in the second half.
"I would have preferred more points but I am happy about the display.
"We played two very good games against two very good teams who will be fighting for the title until the end.
"The second half (against Napoli) we came back with a great spirit and determination to win the match and so the second half makes me confident for tomorrow's game."