Although first-year head coach Jim Schwartz has made it abundantly clear — along with new GM Martin Mayhew in albeit a less verbal manner — that the Lions are more than willing to at least fish the waiver wire, and will probably do so right up until the season opener, there are still plenty of wide open competitions among the players already on the roster.

Here are a handful to watch on the field Thursday night, when the Lions take on the Bills. (And, if you take Schwartz at his word, quarterback isn't necessarily one of those battles. Yes, Matthew Stafford will BEGIN the game, and Brooks Bollinger will take over to hand off the ball. Kevin O'Connell may or may not play. Daunte Culpepper won't play, but Schwartz says that the 20-25 plays the erstwhile starter would get won't make or break the competition.)

1. Running back With the quarterback situation likely limiting the playbook, expect to see the second-, third- and fourth-team backs will get lots and lots of chances to impress. Hampered by injury for much of camp, Maurice Morris hasn't shown much, but may get a free pass, since he's a veteran. Jerome Felton's ability to hammer the ball between the tackles has likely cemented his roster spot, while Terrelle Smith gives the Lions a true blocking fullback. Aaron Brown and Tristan Davis have both shown more flashes on offense than Aveion Cason, but the decision may come down to the other things that they can do.

2. Defensive line Four spots seem more or less settled. Dewayne White and Cliff Avril looked like they were competing for the same spot at left end to start camp, but Jared Devries' injury may have put both in the starting lineup. Jason Hunter has been solid — but not spectacular — as a third end, but the fourth end spot is a crapshoot. It could end up being one of the players — primarily Andre Fluellen or Ikaika Alama-Francis — who have been working outside as the overflow from the tackle competition. Grady Jackson is a given at tackle, but the other starting spot probably comes down to the Lions selecting two or three of the remaining contenders — Shaun Smith, Chuck Darby, Landon Cohen, Sammie Lee Hill, Orien Harris, Fluellen or Alama-Francis — for a tackle rotation. None have really established anything so far. Pass-rusher Orion Martin could sneak into the conversation at end, now that he's been in camp for more than a week.

3. Linebacker Everyone knows the Lions starters at the position, where the team added free agent Larry Foote and trade acquisition Julian Peterson to Ernie Sims, but no one knows any of the backups. Depth at this position is scarily thin. Cody Spencer looked like he had a roster spot in his sights before a knee injury sent him to IR, while rookie DeAndre Levy and even — gasp — the much-maligned Jordon Dizon have shown flashes, but the rest of the guys — Zack Follett, Darnell Bing, Spenser Smith and Rufus Alexander — are just that: just guys. If none of them step up, look for this to be an area of interest when the waiver wire gets flooded after 6 p.m. on Saturday.

4. Offensive line Manny Ramirez has had the light come on this preseason, and gives the Lions a solid third guard, if he doesn't manage to earn the starting job at left guard over Daniel Loper, but other than that remaining battle, the starters seem set. Jon Jansen and Ephraim Salaam seem locks as versatile swing backups, but the last spot or two seems to be wide open. Interior reserves Dylan Gandy and Dan Gerberry have been solid, but may lose out to the experience of Jansen and Salaam. Seventh-round pick Lydon Murtha has all kinds of upside, but keeping him would give the Lions five players who are primarily tackles.