Union Berlin coach Nenad Bjelica on Monday called Real Madrid midfielder Jude Bellingham "a difference-maker" but said veteran Luka Modric was "still the best in the world" ahead of Tuesday's clash.
Bellingham is returning to Germany for the first time since leaving Borussia Dortmund for the Spanish capital in the summer, having emerged as one of the biggest stars in world football
The Englishman, still just 20, is La Liga's top scorer this season with 12 goals, but the Croatian coach was well aware of all of Real's midfield threats.
"He's one of the best players in the world right now. He's playing at the absolute top level" Bjelica said of Bellingham.
"We respect him and we respect every player from Real Madrid. But for me as a Croatian, Luka Modric is still the best in the world.
"Bellingham is one of the biggest, he's in top form, he scores goals, he's a difference maker and is difficult to defend. It'll be a big job for us to keep him under control tomorrow."
Bjelica, a former midfielder, played nine games for Croatia in a career which took him to Spain, Germany and Austria.
The 52-year-old started his coaching career in 2008 and became manager of Union Berlin in November.
On Saturday, Union won beat Borussia Moenchengladbach at home 3-1, their first win in any competition since August.
Bjelica said Union "have a chance" against the 14-time Champions League winners, but need to "deliver a perfect game".
