Haller joined from Borussia Dortmund, though has struggled to make a major impact with Leganes, which currently sit 15th on the LaLiga table.
He told Eurosport France: "My beginning of the season was dotted with issues. But it is part of the hazards of’a career and life. I want to say that time will do its work. You have to be patient and keep working to be more efficient. Because I was annoyed by lots of small injuries over a few days. This was not muscular, but more of the blows I've received.
"These setbacks happen every time in the moments when I feel that I return to the physical plane."
Haller also said: "An attacker needs confidence, to chain matches and to adapt to the team. I'm in a team that is completely different from what I’vd had experienced in the last three or four years (West Ham, Ajax and Dortmund).
"There is also a part of mind: when frustration and lack of confidence begin to settle, it does NOT’ help to perform. But I have to adapt, I take it as a challenge to take up. We must show humility.
"My profile does not necessarily fit the style with which the team currently plays. But it's up to me to earn my place and make myself useful."