The Portugal international departed the Bernabeu earlier this week in a €100m move to Juventus, leaving a sizeable void which has Real circling a number of candidates who they feel can step up in his absence.
Chelsea's Eden Hazard has been linked, as had Neymar before the Spanish giants released a statement ruling out any such interest, but Mbappe remains the man tipped to be the preferred candidate.
However, having only secured his transfer to Paris Saint-Germain last summer in a deal which made him the second highest ever transfer of all time, Real's former midfielder Karembeu is of mind that a deal for the 19-year-old will be anything but straightforward.
“He's a phenomenon. If Real Madrid want to sign him then they'd better be quick!” Karembeu said, via Goal.
Karembeu's statement comes after football consultant Ian McGarry claimed that Real Madrid are fairly confident that they can pursue the France international this summer with PSG under pressure from Financial Fair Play regulations.
He said, via the Daily Star: “With Mbappe it’s complicated but Real Madrid are fairly confident they can peruse him with some success but they are not entirely sure that is going to happen."
The 19-year-old has continued his exponential rise to the top of the game following a stunning World Cup campaign which has seen him notch three goals on the way to the final on Sunday.
Ronaldo's move was likely to have triggered a domino effect, ensuring Mbappe's future will remain under question throughout the remainder of the summer transfer window.