 He scored 25 times in the U-19 Bundesliga West, making him the league's top goalscorer, and helped secure Leverkusen a spot in the national finals, which they lost 1–0 to Hansa Rostock.Towards the end of the season, Lasogga made his senior debut, making five appearances for Bayer 04 Leverkusen's reserves in the Regionalliga West during the 2009–10 season.After just one season with Leverkusen, he left the club, and signed for 2.