[2] At the end of a year-long preparation for the 27th SEA Games, Khairil joined IKLS for the 2014 Brunei Premier League season, scoring two goals from defence for the Kampong Ayer-based team.

[4] Khairil moved to Indera SC in 2017 and shortly after was appointed club captain, replacing Afi Aminuddin who left for Kota Ranger.

[14] Unfortunately, the Brunei under-23 squad which boasted the likes of Azwan Ali Rahman, Adi Said, Yura Indera Putera and Nur Ikhwan Othman failed to earn a single point in Myanmar the following December.

[22] Khairil made his first international appearance for the full national team in a friendly against Cambodia in Phnom Penh which finished 6–1 to the hosts.

[32] Under new head coach Mario Rivera, Khairil was converted into a holding midfielder and impressed in the second game against Laos which ended 1–0 to the Wasps.

[33] He kept his place in the lineup for the two-legged 2022 AFF Mitsubishi Electric Cup qualifying matches against Timor-Leste and played the full 180 minutes as Brunei managed to advance to the tournament proper with a 6–3 aggregate win.

[36] In March 2024, Khairil was selected for the national team to travel to Saudi Arabia for matches against Bermuda and Vanuatu for the 2024 FIFA Series.

[38] The following September, Khairil was chosen for the squad to face Macau at the play-offs to contest a spot at the final qualifying round of the 2027 Asian Cup.

[40] Four days later in the return leg away at Macau, Khairil also came on in the later stage of the game where Brunei posted a 0–1 victory, winning the tie 4–0 on aggregate to advance to the next round.