He was a part of Heimir Hallgrímsson’s side, as they prepared for friendlies against Senegal and Luxembourg. The midfielder made his debut as a second-half substitute, coming on in the 67th minute for Matt Doherty in their game against Senegal.
Phillips then started his first-ever senior game for the Republic of Ireland a few days later, playing 57 minutes in a 0-0 draw against Luxembourg.
Phillips was on loan at St Mirren this season, starting in 33 consecutive Scottish Premiership games and helping the side to finish in the top half of the division before the split. He made his move permanent following the conclusion of his contract.