Speaking about last season's centre-back pairing, as cited by Anfield Watch's Twitter account, Klopp said that his side wouldn't be in the position they are in without Williams and Phillips.
Both players helped the Reds secure a top four finish (Champions League qualification) last season.
"I messaged Rhys Williams and Nat Phillips - we wouldn't be there without them. I remember the final game of last season and they left the pitch with a bandage around the head, cuts on their faces, and that was really a symbol for the whole period," the German said.
"Hopefully nobody forgot how hard we fought to get here. We felt it mentally. We had no centre-halves, had to play midfielders in the last line, then had to use other players in midfield and nothing worked really.
"In the end, we played with two incredible players - Rhys and Nat - but we couldn't use them earlier because they needed time to adapt. So, yes there was a bit of a point to prove and I'm really happy that the boys did that."
“There is a photo stuck in my mind of the final day of last season. It shows Nat Phillips and Rhys Williams applauding the fans in front of the Kop, both of them with bruises and cuts. For me, that image captured best what those boys achieved.” #awlive [lfc] pic.twitter.com/qyl1Sa0mjn
Anfield Watch Verdict
What Williams and Phillips did for Liverpool last season was nothing short of a miracle. They are both good defenders but their efforts to guide the Reds to a Champions League place were amazing.
Phillips helped guide Bournemouth back to the Premier League this season while Williams spent half a season on loan with Swansea before returning to the AXA Training Centre.
The pair are definitely good enough to be Premier League defenders and their time with Liverpool last season proved that.
Unfortunately, the club's current crop of centre-backs are world-class and there is no space for either of them in our squad.