While a lot of people will be paying attention to a certain pair of high-profile wide receivers on the opposite sideline, the Buffalo Bills will be focused on their own corps of pass catchers tonight against the Cincinnati Bengals.

With Terrell Owens joining Chad Ochocinco, the Bengals feel good about what they've got at wide receiver. But the position is one of the Bills' biggest question marks. Lee Evans is clearly the top guy, but who lines up behind him is still uncertain.

Stevie Johnson has been the No. 2 wideout throughout training camp but hasn't locked down the job. Roscoe Parrish looks like the favorite to be the primary slot man in three-receiver formations.

Chad Jackson has made a steady rise up the depth chart with a solid training camp. He leads the Bills with six catches in the first two preseason games. Head coach Chan Gailey singled out undrafted rookies David Nelson and Naaman Roosevelt as pleasant surprises this summer. Another undrafted rookie, Donald Jones, has had some good moments as well.

Meanwhile, James Hardy makes his preseason debut tonight, looking to regain the ground he lost to a foot injury that sidelined him for the first two exhibitions.

The competition has been wide open, but Evans said the time has come for someone to emerge from the crowd.

"I think it's pretty much starting to define itself, and it has to because after this game it's pretty much all downhill until Miami [the opponent for the regular-season opener]," Evans said. "I think what you'll see in this game is probably what you'll be getting. One of them will have to step up and make plays and that's basically the bottom line. But I think it's starting to define itself now."

Besides Evans and Parrish, this is a very young group. Only one of the other seven wideouts on the roster has more than two years experience.

With youth comes mistakes, which Gailey pointed out earlier this week.

"I thought we had improvement," he said. "We are mentally not where we need to be with that crew, but physically there's some talent in that group. We have to continually work with them to get them exactly where we need them to be down in and down out. I'm pleased with where we can be. We're not there yet."

A perfect example of that is Johnson. The third-year pro had a good camp, but he still needs to work on the finer points of the game. He drew the ire of Gailey during the Bills' final night practice at training camp because of a mental error.

Tonight will be big for Johnson, who knows he must be more efficient if he's going to secure the No. 2 role.

"I kind of get lost sometimes trying to be too creative with routes and it kind of gets me in trouble," he said. "But it's just work that needs to be done, be crisper on everything and [Gailey] wants everything to look the same. So I'm going to try to do that work on my routes and make everything still look the same. Like I said, it's just work to be done."

Of the four rookie receivers, no one has stood out more than Nelson. He came out of the pro-style offense at Florida and it shows.

He's not completely polished, but the 6-foot-5, 217-pounder is an imposing target. He runs good routes and has reliable hands. Despite missing practice time with hamstring and ankle injuries, he has consistently made the kind of plays that leave a favorable impression on coaches.

"My mind-set was to come in here and compete every day, get better and show them that I belonged here," Nelson said. "I had people saying there were some question marks about whether I could do certain things, but I used that as fuel to motivate me every day. From Day One, I came out with the attitude to make plays, contribute to the team and not only make the team but make this team better."

The Bills' starters are expected to play at least through the first half, but look for a good rotation of receivers in the game early.

The Bills kept six wide receivers the last two years. Only five made the 53-man roster in 2007, but seven stuck in 2005. That also happened to be the final year Mike Mularkey, another offensive-minded coach, was the head coach of the team.

Quarterback Trent Edwards doesn't know how many receivers he'll have to throw the ball to this season, but he said it's going to be hard to trim any of them off the roster.

"I probably wouldn't want to be that guy making those decisions," Edwards said. "I've been really pleased with those guys ... I think it's been a healthy competition. It's made me and my position better, and it's made those guys and their position better that they're coming out here competing every day. I think that's the atmosphere that Chan wants."

awilson@buffnews.comnull