Jose Mourinho's side were said to be expecting a bid from Madrid for De Gea over the summer, per James Ducker at The Telegraph.
However, the offer failed to materialise, with Zinedine Zidane's side ultimately deciding against signing the goalkeeper this summer, according to Neil Fissler at the Daily Express.
Sky Sports' Guillem Balague has said that while it is true Madrid have ended their pursuit of the goalkeeper for now, "he still wants to go, maybe one day" (h/t Lewis Winter at the Daily Express).
De Gea has proved to be a superb signing for United since joining from Atletico Madrid in 2011, and his importance to the team is highlighted by WhoScored.com:
Meanwhile, current Madrid No. 1 Keylor Navas has come under scrutiny during his time at the Santiago Bernabeu, particularly at times during last season, as illustrated by Opta:
Manchester United manager Jose Mourinho ruled out selling De Gea earlier this summer, but it would be little surprise to see Real Madrid renew their interest in the Spain international next year.
Madrid are also reportedly keeping tabs on Werner as they are keen to increase their striking options, according to La Sexta's Jugones (h/t AS).
Per the report, the club watched the striker in action during Germany's 6-0 win over Norway in FIFA 2018 World Cup qualifying, with Werner scoring a double.
The 21-year-old put in yet another impressive performance for his country, with his recent contributions to the cause neatly highlighted by Squawka:
The RB Leipzig striker also starred for his club last season in the Bundesliga as they finished runners-up to Bayern Munich, with Werner finishing with an impressive goal tally, per WhoScored.com:
While Madrid possess plenty of attacking options, there is scope to bring in another striker. Karim Benzema, who will turn 30 in December, and Borja Majoral are the only true centre-forwards in the squad.
Werner certainly has bags of potential and would also fit with Madrid's policy of bringing in young, exciting players, following the captures of Theo Hernandez from Atletico Madrid and Dani Ceballos from Real Betis this summer.