Phillips clocked the full 90 minutes on Tuesday night as Bournemouth edged out Nottingham Forest 1-0 to seal automatic promotion from the Championship.
The Cherries are back in the big time and Phillips, who signed on loan in January, has been in the thick of it with 16 Championship appearances.
Despite Liverpool being in Champions League action, beating Villarreal 5-2 on aggregate to book a spot in the final, Klopp still found time to send his congratulations to Phillips.
Klopp said at the end of his post match press conference: “Congratulations to Nat Phillips by the way.”
Phillips stepped up for Liverpool when needed last season to help the Reds finish in the top four and qualify for this season’s Champions League.
The centre-back also played for the Reds in the Champions League this season.
Phillips clocked appearances in Liverpool’s group stage wins over Atletico Madrid and AC Milan.
