Everyone knows that Cristiano Ronaldo is declining. His dribbling ability has eroded, his speed lacks the explosiveness of his early years, his overall influence on the game is waning and his physical fitness has taken a hit. The superstar has maintained himself as prominent as ever by evolving his game to that of a poacher despite his propensity for hanging on the wing.

Lionel Messi is also evolving his game slightly, taking less initiative as a goalscorer and more as a playmaker. And yet, the superstar might also be in decline, a storyline no one seems to be looking at.

From a statistical standpoint, the Barcelona superstar had one of his worst seasons to date, even though he managed to win four trophies with Blaugrana and add a fifth Ballon d'Or to his trophy chest.

The boxcar numbers paint a sad story

The boxcar numbers were rather damning - Messi finishing with 41 goals in 49 matches along with 23 assists; the 0.84 goals per game ratio was the worst since the 2008-09 season. His 41 goals this season in all competitions were the lowest numbers since the 2013-14 season when he incidentally won nothing with his club.

However the true story is in the underlying numbers.

The underlying numbers suggest a scarier one

Messi's game can be defined by his ability to stay on the ball and orchestrate his team's play from the midfield. He also loves to dribble and is a maestro in dancing through defenders thanks to his poise and low center of gravity.

But Messi's passes per game also took a hit, perhaps the biggest indication of his waning influence. He only averaged 55.7, a drop from the season before when he averaged 61. 4 passes per game. But even then, those numbers did not represent his best in this category. His passing success rate was also the worst it has been for the superstar since 2008-09 with him completing only 81.9 percent of his passes. Since he making fewer passes per game, one can surmise that this drop in success rate could be attributed to taking more high risk passes. This is backed up by the increase in Messi's long balls per game (3.5 per game), the highest number in his entire career. These passes are high risk and low reward as it stands and might account for his diminished accuracy and limited passes. This of course has everything to do with Luis Enrique's more direct style than in seasons past, but shows that Messi's success rate has dropped a bit in this style.

His key passes per game, which emphasize his importance in creating offensive chances, dropped to the lowest they have been since 2012-13, which featured one of Messi's most offensively dominant seasons. And while the drop off remained around his career average of 2.2 per year, it was still a big drop from his offensive explosion in 2014-15 when he averaged 2.5.

Dribbling maestro no more?

Messi also saw a drop in shots per game, likely the result of deferring more often to Neymar and Suarez. But the statistically category that must give everyone pause regarding Messi is his best asset - dribbling.

Since 2008-09, Messi has not produced fewer dribbles per game in Spain than he did this season. At just 3.5 dribbles per game, Messi was well below his career average. But the plot thickens when you realize that the number has steadily dropped in every season, save for the 2012-13 season; that season seems like the anomaly in which Messi's major underlying stats dropped in favor of higher scoring numbers overall. And yet the 2012-13 season saw a more agile and successful dribbler. This might signal the end of Messi's versatility with the ball on his feet and the need for a more withdrawn position in the midfield.

Injuries also seem to be more common these days with Messi missing time in each of the last few seasons. His body may just be starting to breakdown, leading to the overall drop in performance. And yet he remains a top player in the world, if not the very best. 

The drop in multiple statistics is alarming and at 28 Messi should still be in his prime. Injuries might have limited his effectiveness this season as he sat out for a few months. All in all, next season will provide a better barometer of whether Messi is truly declining or simply had a bad season.