ORCHARD PARK, N.Y. (AP) -- Little went right for the Miami Dolphins' sputtering offense before -- and after -- running back Knowshon Moreno left the field clutching his left arm.
Quarterback Ryan Tannehill refused to pin the troubles on the injury following a 29-10 loss to the Buffalo Bills on Sunday.
There was enough blame to go around for the Dolphins (1-1), who looked nothing like the team that opened the season with a 33-20 win over New England.
"It's tough to lose a guy like Knowshon, but I don't know that affected us," Tannehill said. "We didn't get first downs. We didn't rush the ball. We didn't throw the ball. We didn't catch the ball. We didn't do anything well."
The Bills (2-0) rolled to a home-opening victory courtesy of a big third quarter.
C.J. Spiller returned a kickoff 102 yards for a touchdown, and 9:10 later, Sammy Watkins scored on 12-yard catch that put Buffalo ahead 23-10.
For Miami, the bad news came when Moreno was hurt 11 minutes in on his first carry.
Driving up the middle for a 4-yard gain, he was initially hit on the right side by Nickell Robey. Nigel Bradham then struck Moreno from the left, hitting him directly in the arm.
The injury looked serious, though coach Joe Philbin had no update on Moreno's status following the game.
"Obviously, we would love to have him, but you have to deal with those things," Philbin said. "Injuries happen, so it didn't really impact the game plan a whole lot. Other guys have to step up."
The injury poses a potentially big blow to the Dolphins, who signed Moreno in free agency in the offseason. The former Broncos running back had an NFL-leading 134 yards rushing entering Week 2.
The Dolphins had trouble regrouping after Moreno was hurt.
They were limited to six first downs and 62 yards offense in the opening half, and never advanced past their 41.
Miami's two scores came in the third quarter.
Mike Wallace made a one-handed catch for a 7-yard touchdown, and Caleb Sturgis hit a 34-yard field goal.
Even the Dolphins' special teams struggled.
Aside from Spiller's touchdown, Brandon Fields had a punt blocked in the first quarter, and Jarvis Landry fumbled a punt in the fourth.
"We have to do better," Philbin said. "We gotta protect the punter, number one. We got beat inside. I don't think we touched Spiller. We may have, but we didn't have a good clean shot at him so they must've blocked us well. And we need to catch the ball."
Tannehill went 31 of 49 for 241 yards with a touchdown and interception.
Moreno's backup Lamar Miller finished with 11 carries for 46 yards, while rookie Damien Williams had five carries for 19 yards.
"We made too many mistakes on defense and he was just wide open sometimes," Dolphins cornerback Brent Grimes said.
"Anybody who's wide open can make those plays. We need to tighten up and communicate on defense."
Spiller and Watkins, Buffalo's dynamic Clemson connection, provided the electricity to an already charged-up sold-out crowd.
Spiller, Buffalo's 2010 first-round draft pick, added 69 yards rushing. Watkins, selected with the No. 4 pick in May, finished with eight catches for 117 yards.
The game began with a tribute to Hall of Fame owner Ralph Wilson, who died in March. And it came during an uplifting week in which the franchise's long-term future was essentially secured: Wilson's trust reached a "definitive agreement" to sell the team to Buffalo Sabres owners Terry and Kim Pegula for an NFL-record $1.4 billion.
Dan Carpenter hit five field goals and the Bills had four sacks in helping Buffalo get off to a 2-0 start for the first time since 2011, and only the sixth time since 2000.
EJ Manuel went 16 of 26 for 202 yards in building on his promising performance in a season-opening 23-20 overtime win at Chicago.
NOTES: The Dolphins have lost three straight to Buffalo, their longest losing streak since going 0-4 from 2006-07. ... Carpenter hit five of six field goal attempts, the longest from 38 yards. He hit the left crossbar on a 31-yarder. ... DEs Mario Williams and Jerry Hughes, and DTs Kyle Williams and Stefan Charles each had a sack.
