Drzewinski qualified for the men's 400 m freestyle at the 2004 Summer Olympics in Athens, by finishing second from the Olympic test event, in an A-standard time of 3:51.44. Drzewinski failed to qualify for the final, as he placed fourteenth out of 47 swimmers in the morning's preliminary heats, lowering his entry time to 3:50.97. In the 200 m freestyle, Drzewinski challenged seven other swimmers on the fifth heat, including three-time Olympian Jacob Carstensen of Denmark. He came only in sixth by 0.12 of a second behind Portugal's Luís Monteiro with a time of 1:51.90. Drzewinski failed to advance into the semifinals, as he placed thirtieth overall in the preliminaries.