Season-ending injuries to Virgil van Dijk, Joe Gomez and Joel Matip meant the inexperienced Phillips, 24, and Williams, 20, have been thrown in at the deep end this season, along with 21-year-old January loan signing Ozan Kabak.
Liverpool will move to within a point of a Champions League spot if they chalk up their third straight win, at West Brom on Sunday.
Jurgen Klopp has backed Rhys Williams and Nathaniel Phillips to have bright playing futures
Youth product Williams was in National League North with Kidderminster Harriers last season
Nathaniel Phillips spent time on loan at Stuttgart last term before returning to Liverpool
Phillips, son of former Bolton defender Jimmy, has made 17 appearances, fellow academy graduate Williams 16 while Turkey international Kabak has made 13.
‘All the boys who came in did incredibly well,’ said the Liverpool boss. ‘Ozan came in and played a super part for us, although unfortunately he is now injured.
‘Nat had been playing well for weeks already and Rhys was used mainly in the Champions League because Nat was not on the [initial] Champions League list. But they played together against United and played really well.
Joe Gomez and Virgil van Dijk will both miss the Euros after sustaining serious knee injuries
Joel Matip hasn’t played since Tottenham away in January after coming off with an ankle issue
‘I love what they did, how they maintained concentration against a United front four that’s not easy. They were supported really well by our two full-backs, with a lot of talking [going on].
‘Rhys is a natural talker on the pitch which helps us and I like how we organised ourselves on the pitch. So this year they’ve created two proper careers, which is nice.
‘Both Nat and Rhys will have proper careers and when you’re at an academy that’s not written in stone. They’ve shown how good they are and everything is fine.’