Álvaro Morata has some good options to play important minutes if Higuaín leaves the club, and that's why he's not wanting to leave the club after Sevilla's 10M€ offer, 'As' reports. But if Higuaín were to stay, Morata would likely change his mind quite easily in order to be Sevilla's main striker.
The Andalusian club has sold Negredo to Manchester City in a deal that will be confirmed when the player passes the medical. And now José María del Nido has some money in his pocket to replace him with either Kevin Gameiro or Álvaro Morata. The Spanish striker would be an easier option for Sevilla, since PSG appear to be asking for way too much money for Gameiro.
But, if Higuaín leaves and Morata does accept Sevilla's offer, Real Madrid would need to sign another striker unless Cristiano Ronaldo accepts playing in that position when needed. That way, young players Isco and Jesé would have many more minutes.
According to 'As', Real Madrid could bring back Morata for 11.5M€ after the first year and 13M€ when the second season ends, so it would be a very similar operation than the one that ended with Carvajal playing for Bayer Leverkusen and then returning to the Spanish capital.
The deal doesn't seem very likely right now, but it should be also noted that Real Madrid will reportedly earn around 4M€ from Negredo's transfer to Manchester City, due to Negredo's past in Real Madrid's Academy.