The 25-year-old forward is the club's third signing of the summer after Slavisa Stojanovic and Cyril Kali. The three new foreigners will join Nemanja Lakic-Pesic, Keziron Kizito and Courage Pekuson who already are on multi-year contracts.
Poplatnik arrives from Slovenian top-tier club Triglav Kranj where he finished the 2017-18 season with 16 goals from 34 matches. He has spent most of his career in his home nation except for a half-season detour to Montana, a Bulgarian top division club, in 2015.
He came back to Triglav following an average outing in Bulgaria and has since contributed towards Triglav Kranj's progress to the top-tier of the Slovenian league.
Poplatnik boasts a good goals-to-game ratio in his professional career, having scored 76 goals in 172 appearances since 2012.
David James has filled the holes left by the departure of Iain Hume and Gudjon Baldvinsson with two foreign strikers in Stojanovic and Poplatnik. Blasters have already secured the services of Indian players such as Anas Edathodika, Abdul Hakku, Seiminlen Doungel and Halicharan Narzary.
The Yellow Army finished the 2017-18 season on a disappointing note, finishing sixth in the league before crashing out of the Super Cup. David James, who is on a three-year contract, will be looking to get the club their first trophy this season.
The Kochi-based club will kick-off their pre-season with a three-nation friendly tournament involving Girona FC and Melbourne City on July 24.