There's no doubt that each NFL franchise wants to start the new season strong with all of their players fully energized and ready to go.
Unfortunately that's not always the case, as injuries and other absences can derail a team from playing at their maximum potential.
With that in mind, here's my ranking of the top 15 players who may be unavailable for the 2010-2011 season opener in order of the impact their loss could have.
Note: Most of the players on this list will miss time due to injury, and their rehibiliation period is a mere estimate. I also didn't include players who are projected to miss time well into the regular season.
Dallas Cowboys starting left end Marcus Spears suffered an MCL sprain in practice earlier this month. The injury is expected to sideline him for at least four to six weeks, which makes it very probable that he will miss their season opener against the Redskins.
If that were to be the case, it would be his first game missed in his five seasons in the league.
Jason Hatcher will replace him in the starting lineup.
Minnesota Vikings' middle linebacker, E.J. Henderson, fractured his left femur last season and some believed the injury could be career-threatening.
The good news is that he will be able to play again. Even better, he may see limited action in preseason.
The bad news, though, is that few are seeing a return by their season opener against the New Orleans Saints a legitimate possibility.
The Buffalo Bills' running backs, Marshawn Lynch and Fred Jackson, both suffered injuries that will sideline them for most, if not all, of the preseason. Depending on the rehabilitation process, they could also miss some a few games in the regular season.
With a shaky quarterback situation at hand, the team was expected to heavily rely on a their rushing attack.
However, this setback, will force them to have their first-round pick C.J. Spiller take the majority of the workload. Looking at this from an optimistic perspective, this gives them a great opportunity to test his capability of being a feature back.
The Minnesota Vikings receiver Percy Harvin is, once again, suffering issues with migraines.
Anything could happen in the next few weeks, and it's a big question mark as to whether he'll be able to play in their much anticipated Week One matchup against the New Orleans Saints.
Even though he has returned to practice, head coach Brad Childress had this to say regarding the issue:
"He's feeling better, or he wouldn't be here. Migraine free? I don't know if you can ever say that."
I think Harvin could become Bob Sanders 2.0—a talented playmaker who could frequently miss time due to nagging injuries.
On a side note, teammate Sidney Rice appears to be progressing smoothly from his hip injury and should be ready for the start of the season.
The Dallas Cowboys, right tackle Marc Colombo suffered an injury to his right knee that required surgery. Luckily, he is only projected to miss two to four weeks.
Replacing Colombo will be the inconsistent Alex Barron, who was traded for earlier this offseason.
This could pose a serious problem against the Redskins' relatively stout defensive line.
Raiders running back Darren McFadden's two years in the league have been filled with injuries. Now, his latest hamstring issue only adds to that list.
McFadden and Michael Bush are currently competing for the starting role in Oakland, and this injury gives a clear road for Bush to claim it.
Both of them will be depended on throughout the season to help along Jason Campbell get accustomed to the system.
The Dallas Cowboys have been bitten by the injury bug, and several players including first-round pick wideout Dez Bryant have been victims.
Bryant suffered a high ankle sprain that is expected to keep him out for at least four to six weeks, making him doubtful for their season opener against the Redskins.
The rookie is currently trying to beat out Roy Williams for the No. 2 spot on the depth chart behind Miles Austin, and this injury will hinder him from doing so.
Atlanta Falcons No. 1 cornerback, Dunta Robinson, is currently dealing with a hamstring issue that could sideline him for at least a few weeks.
Similarly to Fitzgerald, he is expected to be back in time for their regular season matchup against the Pittsburgh Steelers. However, we also do know that hamstrings can turn into serious problems if not treated correctly.
Losing Robinson, who signed a six-year, $57 million contract earlier this offseason, would really hurt their defense.
Al Harris, cornerback for the Green Bay Packers, suffered a torn ligament in his left knee that required him to undergo major knee surgery this offseason.
He's said he does expect to play this upcoming season and will be returning to practice sometime this following week.
At the same time, the 35-year-old's availability for their season opener against the Philadelphia Eagles is questionable.
Monday night, in a meaningless preseason game, New York Giants quarterback Eli Manning suffered a nasty hit that resulted in a gash in his forehead that required 12 stitches to seal.
Manning did undergo X-rays that indicated no damage to his head.
"I'll be back as soon as I can," he said. "It's really not an injury. Nothing serious. I really feel like I could go back out and play right now if I had to."
While it doesn't appear to be too serious of an injury, there is a slight chance that it could cause him to miss the season opener against the Carolina Panthers and end his impressive streak of 87 consecutive starts.
Indianapolis Colts' starting center, Jeff Saturday, underwent arthroscopic knee surgery last week in order to remove a "loose body."
Even though those procedures usually take about two weeks to recover from, Colts owner Jim Isray stated it could keep him out of action for up to six weeks.
Until he returns, Jamey Richard should take over at center.
In a Week 17 game against the Houston Texans last season, New England Patriots wide receiver Wes Welker injured his left knee, forcing him to undergo surgery this offseason.
The timeline for his return has been shifty, and some are speculating that he may be back in time for the season opener.
However, there's still a strong chance that will not be the case.
Welker, the most dominant slot receiver in the game, is an integral part of the Pats' offense as he ultimately compensates for their weak rushing attack.
Arizona Cardinals star wide receiver, Larry Fitzgerald, suffered a sprained knee that may sideline him for the remainder of the preseason.
While reports are indicating that he will not miss any regular season action, it is still a definite possibility.
If that were to be the case, it would be disastrous for their offense.
Note, their season opener is against the St. Louis Rams, which should ease some concerns.
Cornerback Darrelle Revis of the New York Jets has clearly displayed his interest to be be given a raise, to say the least.
In fact, his demands are so adamant that today was his 16th day of a holdout that doesn't appear to be ending anytime soon.
According to reports, both sides are far from getting a deal done, and this may drag on into the regular season.
Losing him, immediately eliminates any chances of them remaining a Super Bowl contender.
Brett Favre has decided to make headlines, with yet another installment of his retirement saga.
Earlier this month, there were reports that the future HOF-er was planning on retiring from football...for the third time.
However, as many expert analysts and members around the organization have speculated, there's no way that he doesn't return for his 20th NFL season.
On the other hand, considering the soon-to-be 41-year-old did get ankle surgery over the offseason, could Favre actually be serious this time?
Note: According to reports, he's officially announced his return today. Here's my article on his return.