Rafael Benitez on Monday admitted that improving a team the caliber of Real Madrid “is enormously difficult.” Nevertheless, the Spaniard, who signed as Real coachfollowing the firing of Carlo Ancelotti at the end of last season, has said he will bring in more reinforcements this summer. Prior to Benitez’s arrival, the club addedBrazilian pair Danilo and Casemiro, with the latter returning from a loan spell, but the former Chelsea and Liverpool coach claims there will be more to come.Manchester United goalkeeper David De Gea is understood to be Real’s top target, although the Red Devils are said to want a player-plus-cash deal in exchange for the youngSpanish goalkeeper, who has another year left on his United contract.