Antonio Rudiger believes Chelsea have changed beyond recognition despite his exit from the club being less than a year ago.
The 30-year-old German centre-back moved to Madrid last summer after five years with the Premier League Blues, and since the switch, Rudiger has slotted seamlessly into Carlo Ancelotti's side.
Real Madrid face Chelsea in the Champions League quarter-finals over the next two weeks, but the ex-Blues defender has noticed how much they have changed since his departure.
Thomas Tuchel was fired as manager, but replacement Graham Potter was also axed, so Frank Lampard takes charge until the end of the campaign.
Chelsea have also spent over £600m on new players under new owner Todd Boehly, but they have struggled to click in this campaign, and sit 11th in the top-flight table.
When asked about the Chelsea fixture by Marca, Rudiger said: 'It has changed a lot and I don't really know what to expect... It doesn't look much like the team I played for.
'I expect quality, because they are very good players, but I don't know what else we can find. It won't be an easy game, but we are Real Madrid.'
Real Madrid have also had a difficult season by their own high standards. Twelve points behind Barcelona at the summit of LaLiga, they will be hoping to retain the Champions League title to give their campaign some value.
In a wide-ranging interview, Rudiger said that he acknowledged the pressure that comes with being at Real Madrid, especially based on the trail of success left by his predecessors at the club.
The centre-back said the pressure begins with the trip to Real Madrid's training ground, as well as their high-intensity matches both domestically and in Europe.
Rudiger said: 'In Madrid you have pressure even when you take the car to go to Valdebebas. But I say that as a positive, because I like to have that kind of pressure in my life, I wouldn't want to live without it.
'Madrid is not for any player and I try to be there. I want to spend a great time here.
'You have to be clear about your role in the team. And I know my role. And I have nothing to complain about in that regard. How am I going to complain if the club has been successful like this year after year! I go out to the field and do my job.'
The German defender was also asked whether his pace is impacted by fasting during the Islamic month of Ramadan, but responded: 'Not me, I'm used to it. I don't eat or drink anything, I stick to it to the letter.
'It's not easy, but you train, you examine the head and you end up doing it. It is one of the main weapons that I have, the mentality, and in the end complying with Ramadan is not a problem for me.'
Sandwiched between the two Chelsea matches, Rudiger and the rest of Ancelotti's Real Madrid side travel to 14th-placed Cadiz at the weekend, as they look to close down a huge gap behind LaLiga leaders Barcelona.