Garner was made captain of Western Suburbs for 2018.[5] On 24 June, Garner represented the NSW Residents team, scoring a try in the 36-20 victory.[6] Days later he was elevated to a full-time contract with the Wests Tigers.[7][5] He made his NRL debut in their Round 18 win over the St. George Illawarra Dragons. He continued on to make 6 appearances, 4 of them victories, before the end of the season.
In the 2019 NRL season, Garner played 14 games and scored 7 tries as the Wests Tigers finished 9th on the table. On 19 November, he signed a two-year contract extension to stay with the club until the end of the 2022 NRL season.[8] He said, "It's awesome. I debuted here at the club and to be honest I couldn't see myself playing anywhere else. I love the boys. I love Madge, I love the coaches, so very happy to stay. I look back in the off-season and came to the realisation of what happened. I was very happy with how my year went."[9]
In round 10, Garner scored two tries as Wests Tigers defeated Brisbane 48-0 at Leichhardt Oval.[10] He scored another double in round 14 against Canterbury-Bankstown,[11] and finished with 6 tries from 17 games. His 7 line-breaks were the most of any forward at the club.[12]
His two tries in the first 30 minutes in round 11 against the New Zealand Warriors[13] was the third double of his career. It also equalled the club record of 15 tries for a backrower.[14]
On 27 July, it was announced that Garner would be ruled out for an indefinite period after suffering a syndesmosis injury.[15]
On 24 June, Garner signed a two-year deal with Penrith starting in the 2023 NRL season.[17]
Garner played a total of 20 matches for the Wests Tigers in the 2022 NRL season as the club finished bottom of the table and claimed the Wooden Spoon for the first time.[18]
On 18 February, Garner played in Penrith's 13-12 upset loss to St Helens RFC in the 2023 World Club Challenge.[19]
Garner played 12 games for Penrith in the 2023 NRL season including the clubs 26-24 victory over Brisbane in the 2023 NRL Grand Final as Penrith won their third straight premiership.[20]
On 24 February, Garner played in Penrith's 2024 World Club Challenge final loss against Wigan.[21]
In round 9 of the 2024 NRL season, Garner scored two tries for Penrith in a 42-12 victory over South Sydney.[22]
In June, Garner re-signed for a further two years at the Penrith Panthers.
