Jordy Nelson Head coach Mike McCarthy just announced today that Jordy Nelson underwent a surgery on his knee Monday, and he will miss at least the rest of training camp.

The timetable for his return-to-play has been set at four to six weeks. At this time, all that is known about the surgery is it was an attempt to correct an old “nerve issue” that has bothered Nelson since college, according to McCarthy.

McCarthy is hopeful that Nelson will return in time for the season opener against the 49ers on Sept. 8.

Nelson was plagued with injuries all last season, and subsequently missed four regular season games. Nelson originally suffered a grade-two hamstring strain (a significant number of muscle fibers torn) during a practice leading up to Green Bay's game against the Jaguars in Week 8.

He was held out until Week 11, but ended up re-injuring the same hamstring during Week 13 warm-ups. After trying to play through the injury, Nelson was held out from Week 14 to Week 16.

On the week prior to the Wild Card playoff games, Nelson was on the injury report for a knee injury. However, further details were not given about the nature of the knee injury. Then, Nelson was on the injury report again for an ankle injury leading up to Green Bay’s Divisional playoff game against San Francisco. However, Nelson was active for both playoff games.

It could be argued that all of these injuries stem from the original hamstring injury that occurred in Week 8 of last season. It is common for an athlete to present with a shorter stride length on the leg with a hamstring injury.

When stride lengths are asymmetrical between legs, new and abnormal stresses are placed on otherwise healthy and sturdy ligaments throughout the lower extremity (i.e. knee and ankle joints), and can set those joints up for injury.

It can also be reasonably argued that his undisclosed “nerve issue” may have contributed to his initial hamstring injury in ’12. Nerve issues can lead to sensory and muscle firing-pattern deficits, and can lead to biomechanical abnormalities in the affected lower extremity. These abnormalities can put undue stresses on the three hamstring muscles, and cause a hamstring strain.

So what does this mean to fantasy owners? First, you should be very hesitant to draft Nelson due to the very high risk of him suffering further leg injuries this season. As I have written in earlier articles, hamstring injuries have a high re-injury rate, and they progressively get worse with each subsequent injury. Also, his new knee injury also compounds the risk.

Second, Randall Cobb (despite his recent bicep injury) and James Jones should be moved up your WR rankings following the news about Nelson’s knee surgery. Because the Packers lost Greg Jennings in free agency and Donald Driver to retirement, expect Aaron Rodgers to lean more on Cobb and Jones in the passing game.

I now have Cobb as my No. 9 ranked WR (ahead of Andre Johnson and behind Vincent Jackson), and James Jones just inside the top-20.