Sky Sports pundit and former Liverpool striker Neil Mellor has written in the Liverpool Echo that Jurgen Klopp's decision to substitute Dejan Lovren led to their 3-2 defeat at Southampton last Sunday.
The Reds appeared to be cruising to victory at St Mary's last week as goals from Philippe Coutinho and Daniel Sturridge helped Klopp's side into a comfortable 2-0 half-time lead.
But the German coach withdrew the already-booked Croatian centre-back for fit-again Martin Skrtel, who hadn't played a minute of senior football since December prior to the South-Coast visit.
From there, two goals from Sadio Mane, either side of Graziano Pelle's equaliser, led to a stunning comeback from the Saints, and Mellor says that a rusty Skrtel should never have been introduced.
He wrote in the Liverpool Echo: "Southampton made changes as you’d expect but taking off Dejan Lovren seemed to be a turning point.
"He’d done really well and was helping keep Simon Mignolet and the whole of the defence calm but Martin Skrtel who replaced him has been out of the team for such a lengthy period, he didn’t adjust to the pace of the game and was too busy having to concentrate on himself.
"This spread a little bit of uncertainty in the back four and without a Lucas we didn’t have the personnel to provide that protection."
For the Reds - who had won their previous three Premier League outings - it was a big opportunity missed in their pursuit of a top-four finish.
With fourth-placed Manchester City losing on the day, Klopp's side - who also have a game in hand - would have moved within four points of the Sky Blues had they held on against the Saints.