Next man up for Packers: Brandon Jackson

In forming their 53-man roster, the Green Bay Packers made a couple of odd numerical decisions. Among them was keeping more fullbacks (three) than tailbacks (two). We're about to find out how complex that decision was.

Packers coach Mike McCarthy announced Monday that starting tailback Ryan Grant will miss Sunday's game against the Buffalo Bills because of a "significant" ankle injury suffered in the Packers' 27-20 victory at Philadelphia. Grant has only missed only one game since joining the Packers in 2007, but he is undergoing further tests Monday to determine if his absence will extend beyond this week.

For the time being, at least, that means the Packers will use Brandon Jackson as their starter and slide fullback John Kuhn into an emergency tailback role. The Packers have annually talked up Jackson as a budding contributor, and Sunday he carried 18 times for 63 yards against the Eagles, But this assignment will be much different. Typically under McCarthy, the Packers' No. 1 tailback carries the vast majority of the position's responsibilities.

"I feel Brandon Jackson carried the load yesterday," McCarthy said. "I think there's a lot of evidence right there, recent evidence that he's able to play all three downs, and he will have that opportunity this week versus Buffalo."

Kuhn, meanwhile, ripped off a 12-yard run Sunday as well as a three-yard touchdown dive.

"John's done a very good job with his limited opportunities," McCarthy said. "Every time you put the ball in John's hand he's been productive, and we feel very good about him. He's our third halfback and now will be our second halfback going into Buffalo. I think that's the obvious, without giving away our whole game plan, but I think that's the way we'll definitely go."

This arrangement sounds appropriate as a short-term, stop-gap situation -- especially when the Bills are the opponent. But if Grant is sidelined for an extended period of time, I wonder if the Packers shouldn't re-evaluate their depth. Your thoughts?