Borussia Dortmund midfielder Nuri Sahin has believes his side have not reached their full potential, despite beating Bundesliga champions Bayern Munich 4-2 in the DFB-Pokal Supercup last month.
The Real Madrid owned player, who rejoined the BVB following an unsuccessful loan stint at Liverpool, believes Jurgen Klopp's men still have room for improvement.
"We're heading very much in the right direction," Sahin told Bundesliga's official website.
"I'm looking forward to everything, to every competition.
"We hit a good run of form at the end of last season, but we need to become even more effective - conceding fewer goals and in the best case scenario, scoring more as well."
The Turkey midfielder made 15 appearances for Dortmund last term, scoring three goals.