Injuries are nothing new in the NBA. However, in the past couple seasons, there have been a slight increase in devastating ACL injuries. There were five ACL injuries last season and an average of 3.5 in the decade before, according to the Wall Street Journal. Sample size caveat aside, this is never a good thing.
ACL injuries aren't the only ones threatening the delicate thread between games played and effectiveness for a team's star player. Even though there are three people on this list with ACL tears (and three with knee issues), it is other freakish injuries that can easily raise havoc onto a franchise.
It's rather easy, and perhaps a bit lazy, to judge a player's injury and its effect on their team solely on wins and losses. Instead, it is more prudent to gauge the expectations of the team in the offseason, analyze how their play has been affected by said injury, and put it all together to understand how harmful the injury has been to the team.
Because of that, there were several omissions to the list despite the player's name status and overall greatness. For example, Eric Gordon (knee), Tony Parker (ankle), and Pau Gasol (foot) have missed or will miss their fair share of games, but their injuries haven't affected their teams on a broad level. The New Orleans Hornets have won 21 games this season and they haven't set the world on fire when he has been on the court.
Tony Parker is set to miss the next month or so but if you truly believe the San Antonio Spurs will struggle in the regular season without him...well then you need to watch more Spurs ball.
As for Pau Gasol, it's arguable that Earl Clark has played better or similar to the way Gasol has—not style-wise but production-wise—this season. It doesn't help that Mike D'Antoni has mishandled the whole situation with the benchings as well.
The injuries to star players may not necessarily mean their teams are doomed, or hurt in any way at all. This isn't Bill Simmons' Ewing Theory but there are 10 players, ranked in importance, that have been hurt and severely affected their teams' expectations.