Coach Nuri Sahin speaking as last year's two finalists meet again in the competition's new league phase, revealing that Borussia Dortmund will need more than just a strong mindset when they visit champions Real Madrid in the Champions League on Tuesday.
Meanwhile, Real Madrid won their 15th European Cup in June at Wembley with Dani Carvajal and Vinicius Jr. scoring late to claim a 2-0 victory over a Dortmund team who had threatened an upset win after dominating the first hour.
Speaking ahead of the game, Sahin told a press conference that: "Mentality only is not enough to survive against Real Madrid, especially in this stadium, against the champions of this competition."
"We need everything tomorrow. We need a lot of quality, a lot of self-confidence, mentality of course and also, as we say in Germany, game luck," he added.
"The game has to go our way, so only mentality will not be enough - but of course without mentality we have absolutely no chance here."
On the other side, Dortmund has maintained a winning start to the competition with a home 7-1 thrashing of Celtic earlier this month after they picked up a 3-0 win at Club Brugge in their opening fixture.
Dortmund is currently leading the standings on six points with an impressive goal difference of nine.
"It's only possible (to continue this way) as a collective against this team," Sahin said.
"The lads know what we have planned for tomorrow. We want to be brave and build on the last two games in the Champions League," he added.
The 36-year-old coach, who played for both clubs, will visit Bernabeu for the first time as a coach following his appointment from last summer.
Furthermore, the former Turkey midfielder was Edin Terzic's assistant manager at the club prior to that.
Sahin said: "(Being back at the Santiago Bernabeu) means a lot to me because it was always my dream to play one day for Real Madrid. My son was born in this beautiful city, and I have him with me (here)."
"Now I have the privilege to be tomorrow on the sideline with my childhood club against one of my biggest dreams, so it means a lot to me.
"Even if it was not that long that I played for Real Madrid, it will always remain special for me. Not only for footballing reasons but also family-wise, it's a fantastic thing to be here," he remarked.
In May 2011, Sahin was signed by Real from Dortmund, before he was sent to Liverpool on loan a year later. He returned to Dortmund in early 2013, initially also on a loan deal, before the club made his return permanent in April 2014.
