With the beginning of the NHL's free agency period just days away, trade rumors are out in full force. Multiple rumors that are bouncing around involve Buffalo Sabres' forward Tyler Ennis.

Last season, Ennis flourished after being placed in the middle of a line with Drew Stafford and Marcus Foligno. He finished the season with 34 points in 48 games, but netted 9 goals and 15 assists in the final 22 games of the season. His incredible pace offered some excitement to a disappointing end to the season.

Ennis's statistics suggest he might be the No. 1 center the Sabres have been sorely missing. But the advanced statistics say something else.

In 2010-11, the Sabres' forward had a shooting percentage of 9.5, a season in which he scored 20 goals and added 29 assists. In 2011-12, Ennis finished with an unsustainable 18.3 shooting percentage.

To put that in perspective, of all of this year's 30-goal scorers in the NHL, only two had higher shooting percentages. Take a look:

Evgeni Malkin - 14.7%
Marian Gaborik - 14.9%
James Neal - 12.2%
Alex Ovechkin - 12.5%
Ilya Kovachuk - 11.9%
Phil Kessel - 12.5%

And so on...

The shooting percentage suggests that Ennis will regress from his pace in 2011-12. It also suggests his value will never be higher than it is right now. It only takes one organization to believe Ennis could be their future point-per-game, No. 1 center, despite the good chance that he will not perform on the same level as he did at the end of last season.

Some other factors playing into Ennis's chances to regress are his Quality of Competition statistics. Last year, the only centers on the Sabres that faced easier competition were Luke Adam and Cody McCormick. If he is the Sabres' No. 1 next year, he will undoubtedly see the league's best on the other side of the ice. (the QoC statistic is based on the puck possession numbers for opponents that were on the ice at the same time)

Ennis QoC - -0.025

Compare that to some other top NHL centers:

Ryan Getzlaf - +0.078
Joe Thornton - +0.076
Jonathan Toews - +0.074
Anze Kopitar - +0.072
Pavel Datsyuk - 0.071
Patrice Bergeron - +0.056
John Tavares - +0.056

It is certainly possible Ennis could perform well against similar competition, but it's going to be much harder if he's the No.1.

There's another factor that played into Ennis' success was the explosion of forward Marcus Foligno. Foligno scored 13 points in 14 games in 2011-12. But if you thought Ennis' production was unsustainable, Foligno's is even more so. His shooting percentage was 26.1 percent, about 16 percent over league average and more than twice the league's best scorers. Can Foligno continue to score? Absolutely. Can he continue his pace from last year? Probably not.

One more advanced statistic to consider:

The top 10 teams in the NHL in puck possession made the playoffs. The advanced stats say that when Ennis was on the ice, the opposing team had the puck much more than the Sabres. In fact, Ennis ranked 11th amongst forwards on the team in Corsi On, a statistic that measures possession when a player is on the ice.

Don't mistake what the stats say for the fact that the Sabres could have success with Ennis, Foligno and Drew Stafford on a line next season. All are talented and their chemistry last season was undeniable. However, if you had to make a trade today, Ennis is a player that could be high bang-for-your-buck.

Follow Matthew Coller on Twitter @matthewwgr