Liverpool legend Jamie Carragher fears their title defence is on the line after defeat at Southampton.
Danny Ings' superb second-minute lob over Reds goalkeeper Alisson, from a James Ward-Prowse free-kick, settled the contest against his former club.
Carragher said, "I can't see Liverpool winning the league if they don't bring in a centre-back.
"It's a really tough ask if they don't bring anyone in.
"The fact they played Jordan Henderson at centre-back is not going to do a lot for the two lads on the bench (Rhys Williams and Nathaniel Phillips) and their confidence if they have two midfielders playing there.
"Henderson is not a centre-back. He did well, but it's not his position."