Former Real Madrid striker Karim Benzema believes Kylian Mbappe must learn to play as a central striker in the Spanish capital because he cannot displace Vinicius Junior on the left wing.
Mbappe completed a dream move to Madrid this summer at the end of his Paris Saint-Germain deal, but has not hit top form under Carlo Ancelotti.
The coach has retained Brazil international Vinicius in his favoured position on the wing and has used Mbappe, who prefers to play off the left, down the middle.
"The problem, in my opinion, is that (Mbappe) is not a central striker, even with the national team, every time he plays as a number nine he doesn't feel right, because that's not his position," Benzema told Spanish television show El Chiringuito late Monday.
"On the left, he's got a guy who's at the same level as him, Vinicius, so there is a problem, you can't play Vinicius as a number nine or on the right, because when he plays on the left he makes the difference in every game.
"Mbappe isn't a real number nine. People ask a lot of him and he's under a lot of pressure, this isn't Paris Saint-Germain."
Since arriving from PSG the 25-year-old has eight goals in 14 appearances across all competitions.
Benzema, who won the Ballon d'Or at Real Madrid in 2022 before signing for Saudi Arabian side Al-Ittihad last year, said the striker should keep working hard to adapt to his new role.
"(I'd advise him) don't give up, because I don't think he's going to push Vinicius to move -- he's the best player in the world at the moment," continued Benzema.
"Mbappe needs to get it into his head that today he's a number nine, and forget about the left flank for a while."
Benzema, who joined Real Madrid in 2009 and played there for 14 seasons, warned Mbappe that "if you go two or three games without a goal, you're going to have a lot of problems."
Real Madrid face AC Milan in the Champions League on Tuesday.