A late entrant into Test cricket, Lahiru Gamage is a right-handed fast bowler who bowls at a decent pace and can swing the ball. He has been playing domestic cricket for quite a while in Sri Lanka. Police Sports Club, Chilaw Marians Cricket Club, Nondescripts Cricket Club are some of the clubs he has represented.

In 2014, he took a fifer against Durham in a tour match, which included a hat-trick. With the frontline bowlers not selected either due to injuries or due to them being given a rest, Gamage was rewarded with his ODI cap against the Indians. He did manage to pick a wicket on debut but it wasn't a memorable outing as he was too expensive. Since then, he has made sporadic appearances for Sri Lanka but has been a regular in the A side. An injury to Nuwan Pradeep in 2017 handed him his Test debut in the day-night match against Pakistan. A reasonable outing in both, the ODIs and the Tests, earned him a call-up in the squad for Sri Lanka’s tour of India in 2017.