"If you want to win the league, you need players who are going to perform for nine months and not just one or two months or three games. You need to see the consistency of the players. They need to be competitive in every game," said the Spaniard.
"Sometimes a player thinks one game is not as important but that's not true, every game is important, although you need to analyse the relevant importance of each game as a manager.
"You can't analyse a player totally over the next few games, you need to do that over the whole of the season.
"But you can't change a person. If they don't show character or commitment in these games we have coming up, maybe that shows they cannot do it over nine months.
"We only want players who are committed for the whole nine months. You can't sign players just to play them for three months or just in the Champions League. They must be ready to play every game.
"If you want to earn 85-90 points each year in the league, then you need players who are motivated for every game, not just in cup competitions or one or two games.
"We need players who are competitors in every game and every training session.
"It's impossible to play at the same level all the time. But to work hard and be ready for every game is part of the job. I'm really pleased with my squad, but each player is different and each one needs to learn for the future.
"Maybe this could be one of the biggest weeks of our Premiership season. It's really important that we finish in the top four by winning two or three games, then we can be focused on the Champions League semi-final.
"We've explained to the players how important it is to finish in the top four as soon as possible, but at the end of the day each player is different.
"For some players it easier to be focused, and with others you need to push a little bit more.
"But it's a lot easier to be motivated for a Champions League semi-final than a normal Premiership game."