ORCHARD PARK, N.Y. (AP) LeSean McCoy can finally come clean about the bitter feelings he once had toward 49ers coach Chip Kelly.
Yes, the Bills running back acknowledged he was stung by how Kelly, during his tenure coaching the Eagles, discarded McCoy by trading him to Buffalo in February 2014.
''To sit here and tell you that it didn't affect me last year, I would be lying,'' he said. ''But I'm passed that.''
McCoy can put his emotions aside after getting his personal payback Sunday, when he matched a career high by scoring three touchdowns in a 45-16 win over the 49ers (1-5).
For McCoy, the 140-yard rushing performance was personal because it erased lingering questions whether the NFL's 2013 rushing leader had lost a step last year.
''I think this is the first year that I've really been doubted, as in, `Is this kid good or is he not good?''' McCoy said. ''Yeah, it can definitely drive you.''
McCoy is on a roll having combined for 470 yards rushing and six touchdowns (including one receiving) over his past four games.
It's a stretch that coincides with coach Rex Ryan firing offensive coordinator Greg Roman following an 0-2 start and promoting running backs coach Anthony Lynn.
The Bills (4-2) have won four straight for the first time since opening the 2008 season 4-0. And their running attack is leading the charge. Buffalo's 312 yards rushing against San Francisco was the fifth highest in team history and most since 1992.
The 49ers by comparison are struggling, even with Colin Kaepernick making his debut at quarterback after Blaine Gabbert was benched last week.
Kaepernick went 13 of 29 for 187 yards and a 53-yard touchdown to Torrey Smith. But the offense showed familiar sputters by settling for three field goals, giving the ball up on downs and a punt on six drives that crossed midfield.
And Kaepernick can't help the 49ers' ongoing struggles in stopping the run. San Francisco's run defense has allowed a combined 981 yards and nine touchdowns in its past five games, all losses.
''Yeah, it is embarrassing,'' safety Eric Reid said.
A number of things that stood out Sunday:
McCoy celebrated his third touchdown by handing the ball to guard Richie Incognito, who spiked it in the end zone. It was a reward to Incognito for opening the hole that led to the 18-yard run four minutes into the fourth quarter.
''That's the spoils of victory,'' said Incognito, who said it was the first time he's ever spiked the ball. ''You get in the end zone so many times, you have fun with it. You spike it.''
Kelly isn't saying whether Kaepernick has earned a second consecutive start next week, when the 49ers host Tampa Bay.
''Yeah, we'll see,'' he said. ''I thought he was OK.''
Kaepernick said he tuned out the insults and fans chanting ''USA! USA! USA!'' once he kneeled during the national anthem in continuing his protest against racial oppression and police brutality.
The Bills twice stopped the 49ers on fourth down, including a fourth-and-1 opportunity at Buffalo's 40 with 4:35 left in the third quarter, and San Francisco trailing 17-13. Tyrod Taylor responded with a four-play, 60-yard touchdown drive capped by a 30-yard pass to Justin Hunter.
Bills cornerback Nickell Robey-Coleman forced a fumble by standing up Keshawn Martin during a kickoff return. And the defense had three sacks, upping its total to 20 - one short of last year.
49ers starting running back Carlos Hyde missed most of the second half because of a shoulder injury. He finished with 14 carries for 52 yards.
Kelly didn't have an update on the player's status. Hyde leads the team with six touchdowns.
SHAQ IS BACK?
Bills rookie first-round draft pick Shaq Lawson is eligible to be activated as early as Monday after opening the season on the physically unable to perform list. Selected 19th overall out of Clemson, the pass-rushing threat has been out since May, when he had surgery to repair a shoulder injury that had nagged him in college.
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