He made his Slovenian PrvaLiga debut for Triglav in a 1–0 away loss against Celje on 15 July 2012, coming on as a second-half substitute.
Poplatnik scored his first goal for Triglav a week later in a 1–0 win over Aluminij at Stanko Mlakar Stadium.
On 20 June 2015, Poplatnik signed a two-year contract with Bulgarian side Montana, after a successful trial period with the club.
[2] On 8 July 2018, Poplatnik joined Indian Super League club Kerala Blasters.
[8] Poplatnik made his debut for the senior Slovenia national team on 20 January 2024 in a friendly against the United States.