His only appearance and debut came in the last 2016–17 Indian Federation Cup group stage game against DSK Shivajians coming as a substitute after Vishal's red card in seventy fifth minute but Shillong managed to win 3–2.
Lachenpa made his debut and his only appearance of the league season, on 8 March, against Goa in the semi-final playoffs coming on in the 120th-minute, seconds before the penalty shootout.
Lachenpa made his first appearance of the 2021–22 Indian Super League season, on 7 January 2022, against East Bengal, which ended in a 0–0 stalemate.
[21] He was between the sticks in the club's AFC Champions League debut match, on 8 April 2022, against Al Shabab which ended in a 3–0 defeat.
In group stage game against Rajasthan United, he collided with Bektur Amangeldiev and had to be substituted in a 5–1 win which also resulted in the next match miss.
[29] He played in all games of ISL season keeping seven cleansheets with Mumbai finishing top of the table winning the Winners' Shield.
In playoffs, He played in both legs against Bengaluru FC; the first one ended in a 1–0 loss and the second one in a 2–1 win taking it to penalty shootout where his side lost 9–8.
[31] He also played in 2023 Indian Super Cup group stage games against Churchill Brothers and NorthEast United FC where first one ended in a 2–1 win and second one in a loss by same margin.
[33] On 28 October 2023, in Mumbai's match against Hyderabad FC, Phurba was shown a red card for a rash challenge on Joe Knowles, as the team suffered a 1–1 draw.
[38] In the 2024 Indian Super Cup, Phurba was named Mumbai captain for the first time, in their match against I-League club Gokulam Kerala FC.
[39] This was since regular club captain Rahul Bheke had been called up for the Indian national team for the AFC Asian Cup,[40] and vice-captain Rostyn Griffiths was injured.
While Phurba did make an early mistake leading to Gokulam's star forward Alex Sanchez scoring an easy tap-in, he recovered well and made a number of top saves to keep The Islanders in the game, which ended 2–1 to Mumbai following a last-minute Abdenasser El Khayati penalty.