"Messi has changed the way of kicking penalties this season"
Ben Lyttleton, a penalty-kicker expert and the writer of the book "Twelve Yards, the art and psychology of the perfect penalty", has analyzed for Weloba the problems that Messi is having this 2014-2015 season with the penalties.The writer doesn't doubt: "Messi has changed the strategy to kick penaltis this season". Before  this season, Messi "did a slow run up to the ball, looked to the  goalkeeper and decided at the last moment. He is technically amazing and  mentally very good".
Ben Lyttleton: "Why he has changed the strategy? That's the big question"
Lionel Messi all penalty miss in his career:
https://www.youtube.com/watch?v=3_y6lrdx9J0
The expert explains that there are two ways of kicking a penalty: "being goalkeeper dependent or a goalkeeper independent". Messi, in the past, was a "goalkeeper dependent". It  means that he kicked the ball looking at the goalkeeper until the last  moment and he finally kicked it to the other way. "Balotelli, for  example, also does it this way".
Despite that, this season he has missed the penaltis against Levante, Atlético de Madrid and Manchester City in a "goalkeeper  independent way". "Alan Shearer kicked the penalties in a goalkeeper  independent way, as well as Rickie Lambert or Vidal".  Why did he change the strategy?
As our expert says, "Messi had his own strategy during the last seasons, but I don't know why he has changed it". In  fact, Messi missed a penalty last season in La Liga against Betis in  the 32 fixture. In that occasion Messi did it in a "goalkeeper dependent  way". Moreover, during the World Cup "he kicked the penalties in a  goalkeeper dependent way, and he scored. He did it perfectly".
Here you have some of the penalties Messi kicked in the past. You must watch that he did it in a "goalkeeper dependent way":
https://www.youtube.com/watch?v=2G_kzc_iBB4
And now what?
Lyttleton accepts that "Messi had a routine. When things are not working, you try to change the routine".  After missing three out of six penalties this season, could be Messi  mentally weak? “Score just the 50% is horrible!” assured the writer of "Twelve Yards, the art and psychology of the perfect penalty". 
Lyttleton  reminds, “Maradona was a bad penalty kicker. He missed five penalties  in a row when he played in Boca Juniors… Someone in Barça must prevent  Messi to miss three in a row… As more he miss, more pressure he has”.
Neymar, penalty kicker?
Lyttleton  proposal is that “Neymar should kick the penalties in a bit, despite he  missed the one against Villareal”. In fact, he accepts that “if Neymar  had scored against Villareal, everything would be easier”. Messi should  kick “an easy one to have confidence. Maybe Messi is feeling anxious…  Maybe the relationship with Luis Enrique makes his pressure bigger”,  reminds Littleton.