Bayer Leverkusen coach Roger Schmidt believes that late disruption in the summer transfer window is the reason for his side's poor Bundesliga start.

During a hectic couple of days at the end of the summer transfer window, Leverkusen sold South Korea star Son Heung-Min to Tottenham and replaced the 23-year-old with fresh attacking power.

The club signed Mexico international Javier "Chicharito" Hernandez from Manchester United, and re-united Kevin Kampl -- who spent six disappointing months at Borussia Dortmund -- with his former coach Schmidt.