Michael Owen has warned Liverpool manager Jurgen Klopp that he will have to replace their front three all at once.
The formidable Mohamed Salah-Sadio Mane-Roberto Firmino triumvirate helped fire the Reds to the Premier League title in 2019-20.
But all three are now 29 years old, and Owen told BT Sport he feels the partnership has an expiry date.
He said: 'I think they're going to address it. The issue is everyone's going to become too old at the same time, the front three are all the same age, basically.
'You'll have to - bump - replace all three of them. When there's a glut all going at the same time, that's something Klopp's got to address.'
Although the trio is currently showing no signs of slowing down, forwards tend to wane in their early-to-mid thirties, and Liverpool's other forward options perhaps aren't title-winning standard.
The £40m signing Diogo Jota, 24, has added competition and versatility up front, but striker Divock Origi and midfielders Takumi Minamino and Alex Oxlade-Chamberlain have failed to suggest they could take over from the current front three.
Fellow pundit Rio Ferdinand added: 'There's a place for experience, and a place for youth.
'You could say they could have invested a bit more, added a bit more competition in the forward areas. You'd like that ability to flex your muscles a bit.'