The 27-year-old, who moved to Griffin Park on loan from Czech side Viktoria Plzen, previously played under Rosler at Norwegian club Viking.
"I had a good year at Vikingwhen (Rosler) was there. The first year was really good and I hope I can repeat it," said Fillo.
"It was difficult to playing in Viktoria and I didn't spend so much time on the pitch. Here I will do my best. I'm very hungry to play and want to give 100 per cent for the team.
"It's going to be very tough because the squad is very strong and we have ambitions and work really hard. It's going to be a huge challenge for me."