He has a career high ATP singles ranking of world No.

[2] Samrej represents Thailand at the Davis Cup, where he has a W/L record of 10–8.

[3][4] Samrej won the Asia-Pacific Wildcard Playoff for the 2025 Australian Open,[5] making him the first Thai man to compete in the singles event in a Grand Slam tournament since Danai Udomchoke at the 2012 Australian Open.

[6][7] He lost in the first round to fifth seed Daniil Medvedev in five sets.

[8][9] This biographical article relating to Thai tennis is a stub.