The Buffalo Bills managed to make it through most of two practices before the first knicks and bruises of camp started rolling in. By the time the third practice was over, four players weren't on the practice field.

David Nelson was the headliner; he knocked knees with a defender on a short reception, per The Buffalo News, and left the practice field (on his own power) as a result. Bills head coach Chan Gailey told reporters after practice that the injury was "like a bruise" and did not entail structural damage, but you can safely expect Nelson to get a couple of days off, at least.

Erik Pears and Shawne Merriman did not participate at all on Saturday, but both dings are considered minor. Pears aggravated a groin injury, and was held out as a precaution (replaced in the lineup by Sam Young); Merriman rolled an ankle late Friday, and also was held out as a precaution.

The news is not as routine for defensive tackle Kellen Heard, who left practice with an ankle injury. Gailey told reporters that the injury has been bothering the massive tackle all off-season, and that more tests are forthcoming for the roster hopeful.