The Atlanta Falcons' focus this offseason was to improve an offensive line that was among the worst in the league last year.
In a 32-7 loss to the Houston Texans on Saturday night, the unit suffered what could be a major setback.
Left tackle Sam Baker was carted off the field in the second quarter with a right knee injury. Coach Mike Smith didn't provide any details of the injury after the game and said they would know more on Sunday.
"It's tough," quarterback Matt Ryan said. "Certainly don't know the severity of Sam's injury, we'll wait and see how that shakes out. But you never like to see anybody go down, especially in the preseason."
Baker started 16 games in 2012, but played in just four games last season because of a left knee injury that required surgery in November.
Jadeveon Clowney, the top overall pick in the draft, made big hits behind the line on consecutive plays and Ryan Fitzpatrick threw a touchdown pass to DeVier Posey to help the Texans to the win.
Houston selected Clowney out of South Carolina to form a powerful 1-2 pass-rushing attack with J.J. Watt.
Watt dressed but did not play on Saturday, and Clowney proved too much for Atlanta (1-1). He tackled running back Antone Smith for a 2-yard loss and then beat Baker for a sack on Ryan.
"He's big, a very athletic guy, very quick," Ryan said. "Had two plays that kind of threw us off rhythm with the sack and the tackle for a loss in the run game. So very impressed."
Ryan liked the work of his offensive line despite the sack by Clowney.
"It was encouraging to see what they did up front against a pretty good front seven," Ryan said. "We've still got a long way to go, but I think they're doing a good job."
The Falcons selected tackle Jake Matthews with the sixth pick in the draft and added guard Jon Asamoah to revamp a line that gave up 44 sacks a year ago.
"Those guys have worked really hard and taken their fair share of criticism last season and throughout this offseason," Ryan said. "But those guys have been diligent, they've done a great job and I think they're doing a really good job through the first two games."
Smith has been impressed with the progression of Matthews, who is starting at right tackle.
"I thought Jake did some good things," Smith said. "He got matched up and had some tough battles, but I thought he did a nice job."
Smith wouldn't speculate as to whether Matthews could move to left tackle, a position he played last season at Texas A&M, if Baker is out for an extended period.
Jonathan Grimes returned a blocked punt for a touchdown and Andre Hal returned an interception 64 yards for another score for the Texans (1-1).
Ryan went 3 for 7 in a quarter and a half of work and wide receiver Julio Jones caught two passes in his first live-game action since he broke his right foot in Week 5 last season.
"I thought Julio looked good," Ryan said. "It's good to have him back. Obviously he's a dynamic player for our offense and somebody that we feel like is a game changer."
Fitzpatrick completed 9 of 12 passes for the Texans. He went 3 for 5 and had a 10-yard scramble on Houston's initial scoring drive and rookie Alfred Blue, a sixth-round pick from LSU, finished it with runs of 10, 3 and 1 yard to put the Texans in front.
Sean Renfree replaced Ryan with 6:20 left in the first half and led the Falcons on an 11-play, 66-yard touchdown drive. Renfree, competing with T.J. Yates for the backup job behind Ryan, found Devin Hester on a 12-yard pass with 1:32 left for the tying score.
Rookie Tom Savage played one series before Fitzpatrick returned to lead the Texans in the final 90 seconds before halftime. Fitzpatrick had a 15-yard scramble and then connected with Keshawn Martin for a 31-yard gain to the Falcons 15.
A Falcons' penalty moved the ball to the Atlanta 8, and Fitzpatrick avoided the rush to his right before finding Posey in the back of the end zone with 19 seconds left.
Case Keenum started the second half for the Texans and guided a drive to the Atlanta 22 before Kemal Ishmael intercepted him near the goal line.
Anthony Denham blocked Matt Bosher's punt from the end zone, and Grimes scooped up the loose ball and ran 17 yards for a score.
Yates played the fourth quarter under constant pressure, and tried a futile tackle attempt on Hal's return. Matt Bullough also intercepted Yates, setting up a 33-yard field goal by Chris Boswell.
"It was bad," Yates said of his night. "Not a lot of stuff went right. There was miscommunication out there on the field. Bad passes. Just everything went wrong."
AP Sports Writer Chris Duncan contributed to this report.
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