Mats Hummels says the Borussia Dortmund players are sometimes too quiet on the pitch and “have to be woken up a bit” in order to perform during games.
Dortmund are currently third in the Bundesliga, five points behind leaders Borussia Monchengladbach after struggling for consistency so far this campaign.
A run of two wins in eight league matches during the autumn, including a 3-3 draw at home to bottom side Paderborn, put head coach Lucien Favre’s position under scrutiny.
Successive wins over Hertha Berlin and Fortuna Dusseldorf have eased the pressure on Favre, but Hummels concedes there is room for improvement.
Speaking to Goal and DAZN, the 30-year-old said: “We just look at our performances - and they have been very changeable this season. But nothing is lost yet.
“When we find our shape and go on a run, we can quickly get where we want to go in the table.
“It would be nice if we are in top form when the titles are given out. Until then we have to stay up there.
“Part of us sometimes have to be woken up a bit in games. The 4-0 win against Leverkusen (in September) sounds convincing, but in fact we had big problems in the first 20 minutes.
“We sometimes go into the games and see how it works. Sometimes we flip the switch only when there is no other way. If we get that under control, we can be a top team.
“This is not a thing you change in one or two days. We have to work it out for ourselves. When you look at the training sessions, there has been a development in recent weeks: mentality, attitude and sharpness."
As one of the more experienced players in the team Hummels admits he has a responsibility to demonstrate leadership both on and off the pitch in order to turn improved performances into results.
“I try to fill that role in life and take responsibility," he added. "Especially on the pitch where I verbally try to drive, order and cheer.
“It is already an issue in our team that sometimes we are a bit quiet. That is why it is very important that the leaders take the lead.
“And also, outside of the pitch, you have to perform this role positively and as a role model for appointments, interviews and autograph sessions.”
Despite Dortmund’s apparent struggles this campaign Hummels remains optimistic that they can challenge for silverware both domestically and in Europe.
He also reflected on a eventful year that saw him win the domestic double with Bayern Munich before returning to former club Dortmund over the summer.
“In the Bundesliga, no team really marches ahead. This is mainly because the level - contrary to what is often written - has clearly increased,” he said.
“The small teams no longer travel to Dortmund or (Bayern) Munich to be shot down. They have become much stronger tactically and individually and have a clear plan. That's why the well-known teams lose more points.
“In my view, this year (personally) has been absolutely satisfactory. I fought back at FC Bayern after being in a difficult situation and won the double. In Dortmund I immediately regained my footing.
“My big goal is to round off the good first half of the season in the new year with a title. We want to stay in all three competitions and be there when it matters.”