The two English giants have made contrasting starts to the new campaign, Liverpool sitting top of the Premier League standings and Newcastle being down in ninth place.
Nevertheless, they each possess two of the stronger defensive records in the division, Arne Slot's side conceding just three times while Eddie Howe's team have shipped only eight strikes.
Despite those impressive numbers over an eight-match period, there are reasons for both clubs to add to their ranks at the back as soon as possible.
While Liverpool have Ibrahima Konate and Virgil van Dijk as their standout first-choice partnership, only Jarell Quansah and the versatile Joe Gomez are providing backup.
Meanwhile, Newcastle have been dealing with the long-term knee injuries to Sven Botman and Jamaal Lascelles, who will require time to bed back into the squad upon their respective returns.
Dortmund defender in their sights?
According to Caught Offside, both Liverpool and Newcastle hold an interest in Borussia Dortmund defender Nico Schlotterbeck.
The 24-year-old is viewed as a key member of the German side's defence, making eight starts in the Bundesliga and Champions League this season.
He also recently completed the 90 minutes for Germany as they earned a 1-0 victory over Netherlands in the UEFA Nations League.
If Liverpool and Newcastle were to be competitive in the race for Schlotterback, it is claimed that it would take a proposal of €50m (£41.69m).
Liverpool are said to be ready to put forward a bid of that size, although it is unclear whether Newcastle would want to follow suit.
How would Dortmund react?
Whether Dortmund would definitively give the green light to a sale may depend on whether they qualify for the Champions League at the end of the season.
Schlotterbeck is on a contract until 2027, plausibly leaving Dortmund in a position where they could afford to wait until the following summer to cash in should they so wish.
With Van Dijk's contract situation currently unresolved, Dortmund also know that Liverpool may be prepared to spend over the odds for a suitable replacement if the Netherlands international leaves Anfield.