On February 2, 2015, Tabakis was loaned to Eerste Divisie side VVV-Venlo until the end of the season, but he did not make an appearance with the first team before returning.
[2] He made two appearances with the Under-21 side, and he was also named to the squad for Venlo's first-round promotion playoff matches against Oss, ahead of Eric Verstappen.
On October 3, 2017, Tambakis made his MLS debut, coming on as a substitute for Reynish, who was sent off for denying Minnesota United forward Abu Danladi a clear goal-scoring opportunity.
[7] Tambakis was in the squad because first-choice goalkeeper Brad Guzan was away at international duty, and second-choice Alec Kann was out injured.
[8] After his option was declined following the 2017 season, Tambakis' rights were traded by Atlanta on December 10, 2017 to Sporting Kansas City along with Kenwyne Jones's rights and a 2021 MLS SuperDraft pick in exchange for a second-round pick in the 2018 MLS SuperDraft, Kevin Oliveira, and Tyler Pasher.