The 21-year-old defender was given a surprise start on the final match day against Stuttgart and lasted the full 90 minutes in a goalless draw.
It was a moment that marked a stunning turnaround for Timotheou, who after being with the Sky Blues youth side and earning promotion to the first-team was unable to make an A-League appearance.
Eventually cut from Sydney FC, Timotheou signed for NSW NPL side Sydney Olympic and managed to attract the attention of Schalke.
After making over 20 appearances for their U23's side and scoring two goals, the defender was given his chance in the first-team against Stuttgart.
A chance he admits was almost too hard to get in the A-League - especially growing up in Canberra.
“It seems to be hard in my experience," Timotheou told FTBL last year.
"Then again it shouldn’t necessarily be easy either.
“However if you come from Canberra like myself - I was a bit more fortunate in that I had some exposure as an AIS player - it’s even harder without a local A-League club."
From all accounts, Timotheou's first Bundesliga appearance was a promising one and hopefully the first of many for the young Aussie.