By Scott Garbarini, NFL Editor

(Sports Network) - The Pittsburgh Steelers appear closer to getting their core group back together for the upcoming regular season, though the team will still be without some significant star power for its bout with the Buffalo Bills from Ralph Wilson Stadium.

The Steelers opened camp with several big names on the physically unable to perform list, with running back Rashard Mendenhall, nose tackle Casey Hampton and offensive tackle Max Starks all making their way back from ACL tears and dominating outside linebacker James Harrison hobbled by a knee problem. Though Harrison remains sidelined following a recent scope, the other three have all been activated off the PUP list within the past two weeks.

Mendenhall still won't be ready for Pittsburgh's Week 1 matchup at Denver on Sept. 9, with October the more realistic target date for the two-time 1,000- yard rusher. Left tackle Starks has a chance to be back in action for Saturday's contest, however, which would bolster a front line that's had to undergo quite a bit of reshuffling thus far in camp.

The Steelers may be getting a welcome return from Mike Wallace in the near future as well, with multiple reports indicating that the holdout wide receiver plans to sign his contract offer and rejoin the team as soon as this weekend.

Isaac Redman will serve as Pittsburgh's primary running back until Mendenhall is available, though the capable understudy is dealing with a nagging groin injury that kept him out of Sunday's 26-24 win over Indianapolis. Jonathan Dwyer drew the start in Redman's place and performed well, gaining a game-high 43 yards on eight carries.

Quarterback Ben Roethlisberger threw an interception on the Steelers' opening drive, but bounced back with a 57-yard touchdown strike to wideout Antonio Brown and finished his night 5-of-9 for 81 yards.

Pittsburgh's seasoned defense picked off Colts rookie sensation Andrew Luck twice in the first half, with cornerback Ike Taylor taking his interception 49 yards for a touchdown late in the opening quarter.

The Bills will be seeking to bounce back from last week's 36-14 loss at Minnesota, though an offense that struggled to move the ball in the preseason opener did show some encouraging signs.

Quarterback Ryan Fitzpatrick was a sharp 8-of-11 for 58 yards and connected with wide receiver Donald Jones for a 31-yard touchdown midway through the second quarter. Offseason addition Vince Young, vying to be Buffalo's No. 2 option under center, may have sewn up the job after going 8-for-14 for 123 yards in relief of Fitzpatrick.

Bills head coach Chan Gailey announced a winner in another key camp competition on Tuesday, declaring rookie second-round pick Cordy Glenn the starter at left tackle for the club's Sept. 9 skirmish against the New York Jets.

Buffalo also made some headlines earlier in the week by releasing former NFL Defensive Rookie of the Year Shawne Merriman, limited to a mere 23 games over the last four seasons due to constant injury problems, on Monday.

Saturday's game will be the first preseason meeting between these teams since 2009, when Pittsburgh posted a 17-0 shutout at Heinz Field to extend its lead in the overall exhibition series to 6-2. The Steelers also prevailed in their most recent regular-season clash with the Bills, a 19-16 overtime verdict during Week 12 of the 2010 campaign.