Rybus began his career with Pelikan Łowicz and was in summer 2006 sold to MSP Szamotuły, here played only one season and was than scouted by Legia Warsaw. He made his debut for Legia on 15 November 2007, in an Ekstraklasa Cup match against Dyskobolia Grodzisk Wielkopolski, replacing Marcin Smolinski in the 46th minute. After a good performance, Legia's coach Jan Urban, decided that the young player would join the first team. Rybus debuted in the Ekstraklasa on 24 November 2007. He played the 2007–08 season mainly as a substitute but earned a place in the starting eleven towards the end of the season.
He scored his first goal in the Ekstraklasa in December 2007 against Górnik Zabrze. In April 2008, Rybus scored a brace in a league match against Wisła Kraków.