Liverpool’s struggles in 2017 continued when they lost 3-2 at home to Swansea on Saturday.
Matip, who refused to take part in the Africa Cup of Nations with Cameroon, didn’t get on the pitch against the Swans until stoppage time, replacing Georginio Wijnaldum.
And Aldridge thinks Matip needs to be back playing and starting under Jurgen Klopp soon.
Joel Matip didn't start for Liverpool against Swansea
Jurgen Klopp's side poor start to 2017 continued
Liverpool player ratings against Swansea City
Sat, January 21, 2017
Express Sport rates the Liverpool players' performances from their clash with Swansea Cty at Anfield
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How did the Liverpool players get on against Swansea?
Joel [Matip] could have been the difference there, and he has to start against Southampton
“Joel [Matip] could have been the difference there, and he has to start against Southampton,” Aldridge told the Liverpool Echo.
“We needed his height on crosses and corners against Swansea.
“For the first, Dejan Lovren gets caught under his man. For the second, it's a great ball and credit to Fernando Llorente for a good header, but if there's a bit of Matip's height in there, maybe he gets it away.
John Aldridge thinks Liverpool need to make
“He's been a big player for us Matip and in every game we've lost this season, he's been missing from the starting line-up. That's no coincidence.
“Thankfully the FIFA furore is all behind us now so let's hope he gets back and tightens up that defence. We need it.”
Liverpool turn their attentions to the EFL Cup tomorrow (8pm), when they take on Southampton in the second leg of their semi-final, hoping to overturn a 1-0 deficit.