It seems that Real Madrid are watching Bayern Munich's left-back. He is Alphonso Davies, 23 years old. His contract with Bayern Muchen expires this year, so they don't want to repeat the mistake of Kroos' move. Kroos moved on a free transfer. Munchen does not want Alphonso Davies to move on a free transfer and perhaps this will make Bayern Munich have to let him go this summer. 

Source:  https://www.espn.com/soccer/story/_/id/39278126/real-madrid-eyeing-bayern-davies-summer-move-sources