With C.J. Spiller struggling through the first five games, Buffalo Bills fans have been clamoring for coach Doug Marrone to activate Bryce Brown and give him a chance to see whether he could revive the sagging running game.

Well, they're going to get their wish now that Spiller is likely out for the season with a broken collarbone and Fred Jackson is out indefinitely with a groin injury.

Jackson went down in the first quarter and was in enough pain that he had to be carted off the field. Spiller broke a 53-yard run in the second quarter and broke his collarbone after being tripped. He was carted off, his head covered by a towel.

"He was in a lot of pain," teammate Eric Wood said. "I was just praying for him, telling him to stay strong. I've been there before."

Spiller was taken to the hospital and underwent surgery Monday morning. Jackson, who was on his way to the hospital to get his MRI when the Bills completed their comeback, last-second victory, addressed his own situation Monday.

"I know I'm going to do everything I can rehab-wise to get back as soon as possible," he said. "It's a 3-4 week injury, but we'll try to do some things to get it sped up. I like to think of myself as someone who can get back early. Hopefully I can get back sooner than that. It's not as bad as it could have been. There's no surgery involved; it's just rehab."

So now a running game that until Sunday hadn't topped 100 yards in four games must go with Anthony Dixon and Brown. Both players were acquired in the offseason to provide depth behind Spiller and Jackson, who both have been prone to injury.