Kevin Kolb signed with the Bills this offseason. (USATSI)
The uniform may change but the results seem to stay the same: Kevin Kolb just can't stay healthy. Three weeks after Kolb, who signed with the Bills this offseason, tweaked his knee after slipping on a mat, the team announced that he suffered "concussion-like symptoms" following a hit to the head in Saturday's preseason game against the Redskins.

Kolb arrived in Buffalo after two forgettable seasons in Arizona, where the Cardinals had hoped that he would be their franchise quarterback. Instead, Kolb battled various injuries -- including a concussion -- and only played in 15 games over two years.

With Bills rookie first-round pick E.J. Manuel sidelined for the rest of the preseason while he recovers from minor knee surgery, Kolb appeared to have the inside track for the starting job. That may still be the case, but in a quarterback-driven league, it's only a matter of time before new coach Doug Marrone turns the offense over to Manuel. Partly to see what he has in Manuel, but also because he already knows what he has in Kolb.

Rookie Jeff Tuel, whom the Bills like a lot, is the only other quarterback listed on the depth chart.