"Clearly it's more difficult here than in Spain because the top sides spend big, big money," said the Spaniard.
"This year we have improved a lot. We signed two or three really good players, and also players who've been good for the squad.
"But every year you must improve a lot because the other teams are doing the same.
"I think Chelsea have just spent £16million on a right full-back, even though they got to the Champions League final.
"It's more difficult because after two years of Chelsea winning the league and spending big money, United needed to do the same.
"They started spending big money, and Arsenal were also spending big money on young players.
"We are trying to do the same but because they are continuing to spend big money, it makes it more difficult to catch up.
"You also see Aston Villa, Newcastle, West Ham and Everton spending money and having strong teams. It's not easy to be in the top four and be contenders but because we have a young squad we can try again."