Zinedine Zidane has described Toni Kroos as a "spectacular" player, and one he will single out as an honour to have coached when he retires.
Zidane has coached Kroos since 2016 over two separate spells, and the Madrid boss has no doubt that the Germany international will go down as an all-time great midfielder.
"He will be remembered as a spectacular player, one of the best in the world in his position," Zidane told Real France.
"When I arrived, well, you can imagine, I was really happy to be his coach.
"It's true, when I retire I will be able to say that I trained Cristiano [Ronaldo], [Gareth] Bale, [Luka] Modric, [Sergio] Ramos. But I will also say I coached Toni Kroos.
"It is impressive to see him train every day. How professional [he is]. Talking about him is talking about someone extraordinary."
Kroos' main skill, according to Zidane, is his patience and composure, saying that the midfielder is a player who leads by example.
"He is so good that he could play as a six or even as a 10," Zidane added. "You put him in and he adapts. His main virtue is his serenity, he's calm.
"He's not nervous and loves reaching out to shoot from distance as much as making a back pass. The ease with which he plays with both feet is fascinating to me. You could come to think that he's a natural left-footed player.
"Toni is a very quiet and reserved boy. But when he speaks, he speaks to anyone: his coach, managers, teammates. He does not stop. I have seen many discussions in which his participation has ended up being key."
Madrid did not fare as well in the Champions League, however, as they were eliminated in the last-16 by Manchester City.
After his side's elimination, Kroos vowed to not watch the rest of the Champions Leagu e — a competition that was eventually won by his former side Bayern.