As the Bills training camp progresses, there have been heartening signs all over the field, especially as many of the walking wounded are returning to full health.

Oft-sidelined center Eric Wood, who has been limited to individual drills during his slow, careful road to recovery, was finally taking snaps with the first team. Yes, he only took two, but it’s still a sign things are progressing. Stud running back Fred Jackson is reporting no lasting effects from the broken leg that sidelined the 31-year-old’s career best season in 2011 and Steve Johnson is running routes and snatching passes like he never had a groin tear. Even Marcus Easley looks healthy for the first time since he came to Buffalo (he suffered a knee injury that kept him out year one, then a heart ailment the following season that almost destroyed his entire NFL career).

So far this training camp, the only real injury news was David Nelson being down for a few days when Mario Williams rolled up on his leg and strained his tendon, but now comes news that sophomore linebacker Kelvin Sheppard will be sitting out a couple of days, or more, for some reason.

That’s about all the information Coach Chan Gailey gave the media on Sheppard, who was slotted to be the starting middle linebacker in 2012 after a rookie season that saw him get 70 tackles, a pass deflection, and a safety. According to Gailey’s statement, Sheppard has a “situation he’s dealing with” and that it’s “medical”, but he refused to say more when pressed. Gailey has never been one to bandy about the personal health issues of his players in the media, but to be so guarded in his statement when asked about Sheppard has some questioning how bad the injury might be.

There’s no real panic in Buffalo yet, as the perceived lack of talented options at linebacker coming in to camp has been assuaged by the fine performances of Arthur Moats and, surprisingly, fifth round pick Tank Carder (according to Chan, "[Tank] has gotten his hands on more passes defensively than maybe any other player to this point, which has been pretty impressive.”). Add to that the consistently fine play of Bryan Scott over the years (he’s switching from safety to linebacker this year, but won’t have to change much about his style of play really), as well as the continued progression of fourth round pick Nigel Bradham (he was a physical freak at Florida State and a vicious tackler) and Bills fans shouldn’t be too worried about this mystery ailment, but it’s still enough to raise an eyebrow.

For now, all we know is Sheppard, slated to lock down the center in the new 4-3 offense under Dave Wannstedt, will be sitting for the next couple days, maybe more, and has been replaced largely by Scott McKillop (a player who needs to show something soon unless he wants to be among the first cut).

Otherwise, the Bills seem to have shaken off their injury bug for now. The season's still a long way off, though.