Jonathan Woodgate has backed Kylian Mbappe to "flourish" at Real Madrid and "be even bigger than he is in Paris Saint-Germain" if he makes the move, but the regeneration of Los Blancos' midfield is of greater concern to the former defender.
Mbappe is widely expected to leave PSG for Madrid on a free transfer when his contract expires at the end of the season.
The World Cup winner, who has 10 goals and nine assists in Ligue 1 this term, would boost Madrid in attack, but Carlo Ancelotti is not exactly short of firepower – his side's 47 goals the most in LaLiga and eighth-most in Europe's top five leagues.
And in striker Karim Benzema and winger Vinicius Junior, arguably Madrid's best two players occupy the positions Mbappe likes to operate in.
Benzema is 34 but has never been better, scoring 17 and assisting seven, with only Mohamed Salah (25) topping his 24 goal involvements in Europe's top-five leagues. The ever-improving Vinicius has 12 goals and five assists.
Asked by Stats Perform about Mbappe's potential transfer, Woodgate turned his focus instead to the middle of the pitch, where 32-year-old Toni Kroos (1,261) and 36-year-old Luka Modric (1,196) rank second and third for minutes played.
"[Mbappe] will be the biggest signing of the summer, if it goes through," said Woodgate, who played for Madrid between 2004 and 2007. "On a free transfer as well, it's incredible.
"He is a Galactico signing, one of the best players in the world, he'll flourish in Madrid, he'll be even bigger than he is in Paris Saint-Germain.
"But what concerns me in Madrid is with the likes of Modric, Kroos and Casemiro. That three in midfield are all getting to that stage where they're 35, 34 and then Casemiro. They need to start replacing them.
"Okay, they've got [Federico] Valverde, whatever, but that's the main area they need to start recruiting at.
"That three has been around for years and years and years. It's an incredible three in midfield, so it'll be interesting how they replace them three moving forward."