With the departure of Hyrulnizam to Warriors, Khairulhin assumed the role of second-choice custodian behind Izwan. He made his debut as a substitute against T-Team on 11 May 2013.[4]
In total, Khairulhin made less than 10 appearances for LionsXII from 2012 to 2015.[3]
Hougang United
Following the exit of the LionsXII from the Malaysia Super League, Khairulhin signed for Hougang United for the 2016 S.League season following the advice of former head coach and Singapore legend Fandi Ahmad. He started the season as the first choice goalkeeper for the Cheetahs, keeping 2 clean sheets in his first 3 games.[5] After 12 games, Khairulhin had kept 4 clean sheets, more than any other local custodians in the league.[6] He made 22 appearances in total over the entire season and was retained for the 2017 S.League season.[7]
Khairulhin retained his position as starting goalkeeper for the Cheetahs, conceding only 16 goals in 14 S.League games.[8]
Following his exploits early on in the 2016 S.league season, Khairulhin was called up by national coach Bernd Stange for centralised training.[3] Khairulhin was called up for the training tour in Japan and the friendly against Cambodia in 2016 by coach V. Sundramoorthy.[9][10]