ESPN NFL

San Francisco quarterback Alex Smith knows his team will likely need an improved performance from its offense this week, and the 49ers will try to deliver that against an opponent missing a major part of its defense.

The New York Jets won't have star cornerback Darrelle Revis to help stop Smith and the rest of San Francisco's playmakers Sunday or likely the rest of the season.

San Francisco (2-1) scored a combined 57 points and committed one turnover while winning each of its first two games but couldn't keep things going last Sunday in Minnesota. The 49ers gave the ball away three times, including Smith's first interception in a team-record 249 passes, and managed only one touchdown in a 24-13 loss.

They were also held to 89 rushing yards after totaling 334 in their first two games.

"When you're only putting up 13 points on offense, it's usually not going to get it done. We've got to get better," Smith said. "We didn't execute well enough in the red zone. We kicked too many field goals down there. We would love to get (touchdowns). There's a lot we can get better on."

San Francisco will try to make those improvements against a Jets team seeking to overcome the loss of Revis -- one of the best defensive backs in the league.

The three-time All-Pro tore his left ACL in a 23-20 overtime victory over Miami on Sunday and likely won't play for the rest of the year, although coach Rex Ryan wouldn't completely rule out his chances of returning.

With Revis out, New York (2-1) will try to rely on a combination of Antonio Cromartie, whom Ryan deemed "a No. 1 corner," and 2010 first-round draft pick Kyle Wilson.

"This is a team game, and as a team, we've got to step it up," Ryan said. "I think we'll respond. We certainly have to accept the challenge, and we're going to come out and compete. We might do it a little differently, but we're certainly going to give it our best shot, without question."

The Jets lost Revis in the third quarter of last week's game but held the Dolphins to only a field goal in the final 25:38 of regulation and overtime. They also got a little luck when Dan Carpenter missed a potential winning field goal in extra period and Nick Folk's blocked attempt was negated by a Dolphins timeout.

Folk followed by making the game-winner from 33 yards.

The Jets lost 27-10 in Pittsburgh on Sept. 16 when Revis sat out with a concussion and gave up 265 passing yards. They allowed less than 200 in each of their two wins and will face a deep receiving corps that includes Michael Crabtree, Vernon Davis, Mario Manningham and Randy Moss.

"Everybody's got to step up," Ryan said. "Whatever it takes, that's what we're going to do. We have enough to get it done here. ... This football team is a bunch of competitors. We will find a way to get this done."

San Francisco has tried to help itself for this game by practicing at Youngstown State in Ohio instead of flying back to California and then going cross-country to New York. The 49ers did that last year between the third and fourth weeks of the season and rallied for a 24-23 victory in Philadelphia on Oct. 2 as part of an eight-game streak.

"We got very close and that's kind of where we got into our groove last season," left tackle Joe Staley said.

During Wednesday's practice, Pro Bowl linebacker Patrick Willis was in full pads after leaving in the fourth quarter of Sunday's loss with a leg injury.

Running back Brandon Jacobs (knee), who has yet to make his debut for the team, also practiced as did Ted Ginn Jr. (ankle). Nose tackle Isaac Sopoaga remained out with a knee injury.

The 49ers are visiting the Jets for the first time since a 22-14 defeat on Oct. 17, 2004. San Francisco topped New York 24-14 in the most recent matchup Dec. 7, 2008.

The 49ers have won nine of 11 all-time meetings.