Lionel Messi did not have a great World Cup. He pulled off some heroic moments for Argentina in the group rounds before slowly fading into the background as the competition grew stronger and the pressure mounted. He was invisible in the biggest game of his career, and his legacy was forever tarnished by the defeat in the final.

Now, he returns to Barcelona for the 2014-15 season and a chance to re-establish himself as the world's top player. But Messi enters the season with a lot of huge question marks, and none is bigger than his form. The Argentine superstar has seen his goal scoring decrease noticeably over the last few years mainly because of continued injury problems. During the World Cup, his fitness declined, and there were several images of the superstar vomiting on the pitch. It seemed as if his body were giving out completely.

To put things into perspective, Messi scored 73 goals in 60 games during the 2011-12 season before dropping to 60 goals in 50 games the following year. In his most recent campaign, he scored 41 in 46. The goals per game average is not a particularly huge drop just looking at these numbers. But his goal scoring in Spain's soccer league La Liga, where he gets most of his tallies, was rather precipitous in 2013-14. He played 31 games and scored 28 goals. Not a bad number by most standards but worrisome by Messi standards. A year earlier he played 32 games and scored 46.

Those causes for concern will only grow with the inclusion of Luis Suarez and Neymar on the squad. While Messi has steadily "declined," the Uruguayan has risen. Suarez went from scoring 11 goals for Liverpool in 2011-12 to score 23 in 2012-13. In his most recent season, he scored 31 goals in 23 matches. Comparisons to Messi might look ridiculous considering the difference in the number of goals, but Suarez did play far less games than his new teammate.

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Suarez will likely be slotted in as the team's leading striker, meaning that he will get more opportunities to score. It is unlikely that Suarez was brought in to simply make passes backward to Messi. If he gets the ball, then Suarez will score.

Suarez may be out for the first few months of the year, but the recent lightening of his sentence is hugely favorable. He can still practice with his teammates, meaning that he will be in far better shape when he makes his debut at the end of October. If this were not the case, then Suarez would probably need a few months to get back in top form. Under that circumstance, his chances of topping Messi would be minimal. But that is no longer the case for him.

Then there is the issue of Neymar. The Brazilian endured a rather weak year with Barcelona in 2013-14, but at the age of 22, he is undoubtedly on the rise. The hope is that one day Neymar will be the best player in the world.

Neymar had promising moments with Barcelona, but he actually played best when Messi was injured. Now that the Argentine is back, Neymar will need to strike a balance and find a way to play his game while also cooperating with his teammates. Luis Enrique, who is expected to employ a more direct style, could also find a way to better accommodate the Brazilian's quick pace and directness.

But for him, there should be no precipitous decline; there should only be growth.

Messi is only 27 and should be entering his prime years. But his recent years and questions about his physical fitness surely cause concern over his future. There is no doubt that he will eventually be supplanted as the offensive leader of his club. And that moment could come as soon as 2014-2015 season with the arrival of Suarez and a newly motivated Neymar. Unless Messi turns things around and regains the form and physical fitness that has made him a world-beater, then he could be facing a massive disappointment.

Do you think Messi remains the main man at Barcelona in 2014-15? Or will Suarez and/or Neymar surpass him?

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