Liverpool icon Kenny Dalglish believes Virgil van Dijk and Alisson are the key players behind the club's season.
The Reds are currently top of the Premier League table by two points ahead of reigning champions Manchester City.
Jurgen Klopp's side have conceded a league-low 18 goals, and Dalglish says the presence of van Dijk and Alisson has contributed to their improved defence.
He told Liverpool's official website: "You never know when your success is going to come, but certainly the January transfer window when they brought in Virgil and the summer when they brought in Alisson Becker - two fantastic signings.
"Two people with real presence and stature, as well as stopping them at one end and Virgil's knocked in a couple at the other end!
'And when you're confronted with Alisson Becker one on one, he's an imposing feature to try and knock it past. So they're two areas we've strengthened over the last 12 to 14 months, and that's fantastic for us."