Having come through the age groups for the Central Coast Mariners Academy, Bayliss was promoted into the NPL First Grade team for the Mariners for the 2022 season, with the Mariners competing in the newly renamed NSW League One competition, the second tier in the National Premier Leagues NSW system.[3] Bayliss made an immediate impact for the team, ending the season as the equal top scorer in the competition with 13 goals in 22 appearances.[4] The season saw the team win the Premiership for finishing top of the table and achieve promotion to the top flight,[5] however losing the Grand Final 2-1 after extra time to St George City.[6]
In January 2023, Bayliss was signed on a scholarship contract with the Mariners, joining his older brother James in training with the Mariners first team squad for the 2022-23 season.[7] Bayliss continued his fine form into the 2023 NPL season, with the team now competing in the top flight following the previous season's promotion. Bayliss was a key member of the team, scoring 9 goals in 21 appearances. Bayliss had a standout performance against North West Sydney Spirit at Pluim Park, being involved in all 4 goals for the side in a 4–2 victory, initially with two assists and then scoring two goals in two minutes late in the match to secure the victory from a position of 2-2.[8] However, that match would be his penultimate appearance for the club, appearing one final time against Sydney FC Youth. Bayliss scored again in his farewell match, and was clapped off by teammates and supporters at the end of the match.[9]
His departure from the club was confirmed the following day.[10]
Newcastle Jets
Following his surprise release from the Mariners, it was announced the following day that Bayliss had signed for F3 Derby rivals, Newcastle Jets.[11]
On 17 July 2023, Bayliss made his professional debut in an Australia Cup play-off match against Melbourne Victory at Larrakia Park in Darwin, coming off the bench as Newcastle won on penalties to qualify for the 2023 Australia Cup round of 32.[12] Bayliss also made his A-League debut in Newcastle's opening match of the season, a 2–2 away draw against Perth Glory.
Newcastle Jets would announce on 24 June 2024, he had signed a contract extension for 2 more years.[13]
Lachlan's brother, James, also played for the Central Coast Mariners, making 13 A-League appearances. The brothers featured together in the Mariners NPL first grade sides in 2022 and 2023.[citation needed]
