Andre Johnson's injury could allow somebody else to step up and make plays for the high-scoring Houston Texans. Ryan Fitzpatrick has been doing that for the Buffalo Bills, taking advantage of the opportunity he got when Trent Edwards went down.

With both teams seeking their third straight win, the Texans may be without their Pro Bowl receiver Sunday against the Bills, who have gotten some much-needed steady play at quarterback from Fitzpatrick.

Houston (4-3) won for the third time in four games last Sunday, 24-21 over San Francisco, but Johnson suffered a bruised lung and is listed as day to day. He will undergo several blood tests to make sure he is recovering properly.

The three-time Pro Bowler has 38 catches for 634 yards and four touchdowns. If he misses any time, Kevin Walter and David Anderson will get more opportunities in an offense that is averaging 26.6 points per game since a season-opening 24-7 loss to the New York Jets on Sept. 13.

Tight end Owen Daniels' role would likely also increase. He has had a strong season, with 38 catches for 497 yards and a team-high five TDs.

"He's finding the holes in the defense and I've been trying to get him the ball so we can make plays, and he's been doing an excellent job," quarterback Matt Schaub said.

It would take a group effort to make up for the loss of a top target such as Johnson. Buffalo (3-4), meanwhile, probably could have used a change at quarterback far before Edwards suffered a concussion in the second quarter of a 16-13 win over the Jets on Oct. 18.

Edwards, who will miss his second straight game, has struggled, losing nine of the last 12 games in which he has taken the majority of the snaps. Fitzgerald, signed by the Bills as a free agent in the offseason, has won five straight, including three to close last season with Cincinnati while replacing injured starter Carson Palmer.

Fitzpatrick has helped Buffalo win two in a row, the most recent a 20-9 victory over Carolina last Sunday, and coach Dick Jauron has refused to commit to who will start once Edwards is healthy. Fitzpatrick doesn't have gaudy passing numbers, but has mostly avoided turnovers while still taking occasional shots down the field.

He has completed 21 of 47 passes for 239 yards with two TDs and an interception.

Schaub, meanwhile, has keyed Houston's improvement. He has already set a franchise record with a career-high 16 TD passes this season.

Schaub had two touchdown throws versus the 49ers, and it was his first game without an interception since Week 2.

"He doesn't turn the ball over," coach Gary Kubiak said of Schaub, who has five INTs this year. "That's the difference in us winning and losing."

Houston's defense has allowed six passing TDs in the last three games, but it has gotten vastly improved play against the run. The Texans allowed an average of 48.5 yards rushing in their last four games after surrendering an NFL-worst 205.0 in their first three contests.

"It's been very good for the past month," Kubiak said. "I think that's going with the success of our team here in the past few weeks because our defense has stepped it up and played so well. We had a lot of ground to make up and hopefully we can keep going."

Houston, though, is still surrendering too many points, allowing an average of 22.0 in the last three games. The Texans gave up three touchdowns to San Francisco after quarterback Shaun Hill was benched for Alex Smith at halftime.

"We're good, but we still strive to be great," Houston linebacker DeMeco Ryans said. "We've got to get consistent and play the entire game. We do have the potential to be great. We have the right guys and the right goals."

This will be the first meeting between the Texans and Bills since Nov. 19, 2006, when Buffalo won 24-21 at home. Lee Evans had 205 yards and two 83-yard TDs in the first quarter for the Bills, finishing with 11 catches for 265 yards.

Evans had a season-high five catches for 75 yards and a touchdown last week.