Halfway through the preseason schedule, the roster is showing some signs of sorting itself out. The starting 22 is seemingly all but set, with Keenan Lewis (cornerback), Max Starks (left tackle) and David DeCastro (right guard) apparently taking starting spots. Also, WR Mike Wallace reportedly will report to the Steelers in the coming days, finally ending that drama.

Still, the back end of the final active roster still is in some state of flux. Here is how the roster appears to be shaping up:

Stock rising: LB Adrian Robinson. The undrafted rookie from Temple made plays in practice and in preseason games and has displayed an NFL-level athleticism. The 6-1, 250-pound Robinson plays a "glory" position in the Steelers' defense, but one that has a glut of players in front of him on the depth chart. Still, he's in the mix -- and his chances are helped by the fact LBs James Harrison and Jason Worilds remain on the PUP list.

Stock falling: P Jeremy Kapinos. The six-year veteran has been unable to punt over the past three weeks of camp, but the more alarming development for Kapinos has been how well Drew Butler has punted during the preseason. A rookie from Georgia and the son of former Bears K Kevin Butler, Butler has averaged 47 yards per punt in two preseason games. Butler has the pedigree of being a top college punter and also has shown an adeptness for pinning kicks inside the 10 during practice. That would spell trouble even for a healthy Kapinos.

QB -- In: (3) Ben Roethlisberger, Byron Leftwich, Charlie Batch. Out: Jerrod Johnson.
Johnson hasn't done enough to impress coaches enough to unseat a reliable veteran such as Leftwich or Batch. Perhaps just as important, he hasn't done enough to impress other teams' front offices enough that he would be claimed if cut. Johnson is a good practice squad candidate.

RB -- In: (6) Isaac Redman, Rashard Mendenhall, Jonathan Dwyer, Chris Rainey, Baron Batch, Will Johnson (FB). Out: Jason Ford. Mendenhall was removed from the PUP list last week, which will require the Steelers to use a roster spot on their starting running back when the regular season begins. That creates a logjam in the race for roster spots, and it could leave Batch in a precarious position. Still, coaches like Batch for his versatility, and he's a popular lockerroom presence. In the end, Batch will likely be spared the chopping block because he can contribute on a variety of special teams -- but he can still prove his worth as a running back, too.

WR -- In: (5) Mike Wallace, Antonio Brown, Emmanuel Sanders, Jerricho Cotchery, David Gilreath. Out: Derrick Williams, Marquis Maze, Tyler Beiler, Jimmy Young, Toney Clemons, Juamorris Stewart, Paul Cox. Gilreath might have been the odds-on "favorite" to seize the No. 5 receiver's job through the first three weeks of camp, but it was more of a situation where he was "winning" it by default. A strong showing in a preseason win over the Colts Sunday solidified the claim for a roster spot for Gilreath, who is an option in the return game.

TE -- In: (3) Heath Miller, Leonard Pope, Jamie McCoy. Out: David Paulson, Justin Peelle. Suspended for the first four games: Weslye Saunders. Peelle was signed Aug. 13 after David Johnson was lost for the season with a knee injury. The race for the third tight end spot behind Miller and Pope is up for grabs. Paulson is a practice squad candidate if he doesn't make the active roster.

OL -- In: (9) Maurkice Pouncey, Willie Colon, Marcus Gilbert, David DeCastro, Mike Adams, Max Starks, Ramon Foster, Doug Legursky, Trai Essex. Out: Chris Scott, Kelvin Beachum, Kyle Jolly, John Malecki, Ryan Lee. With rookie Adams failing to blow coaches away in his audition at left tackle, Starks was given the job. Adams was shaky enough in two preseason games that the Steelers might elect for the comfort of a veteran in Essex as insurance.

DL -- In: (7) Brett Keisel, Ziggy Hood, Casey Hampton, Steve McLendon, Cameron Heyward, Alameda Ta'amu, Corbin Bryant. Out: Al Woods, Kade Weston, Ikponmwosa Igbinosun, Jake Stoller, Mike Blanc. The top five along the defensive line will play significantly, and Ta'amu's roster spot is secure based on potential alone. A roster spot might be sacrificed based on the makeup of special teams units, or the status of running backs Mendenhall and Batch.

LB -- In: (8) LaMarr Woodley, Lawrence Timmons, James Harrison, Larry Foote, Jason Worilds, Stevenson Sylvester, Chris Carter, Sean Spence. Out: Adrian Robinson, Brandon Johnson, Mortty Ivy, Ryan Baker, Brandon Hicks, Marshall McFadden. At this point of training camp, there is legitimate reason to doubt whether Harrison and/or Worilds will be ready for the season opener. Both remain on the PUP list, and it's possible -- if not probable -- that at least one will start the season that way. If so, that opens up a spot for Robinson, an undrafted free agent who has shown an ability to make plays.

DB -- In: (9) Troy Polamalu, Ike Taylor, Ryan Clark, Keenan Lewis, Cortez Allen, Ryan Mundy, Will Allen, Curtis Brown, Damon Cromartie-Smith. Out: Robert Golden. Myron Rolle, Walter McFadden, Terrence Frederick, Josh Victorian, Andre Freeman. Undrafted rookie Golden has flashed potential, but he probably could slide seamlessly onto the practice squad. The final 1-2 roster spots here likely will be determined by a player's ability to contribute on special teams.

Special teams -- In: (3) Shaun Suisham (K), Jeremy Kapinos (P), Greg Warren (LS). Out: Drew Butler (P), Daniel Hrapmann (K), Matt Katula (LS). Kapinos' back issues have lingered long enough that Butler is close to taking the field as the punter Sept. 9 in Denver. Hrapmann made four second-half field goals at Heinz Field Sunday against Indianapolis but is still viewed as a longshot to unseat Suisham.

Follow Steelers reporter Chris Adamski on Twitter @CBSSportsNFLPIT and @BuzzsawPGH.