Re-signing cornerback Keenan Lewis should be one of Pittsburgh's top priorities this offseason . (US Presswire)

When starters or regulars miss 60 games due to injuries and players who, at minimum, would’ve contributed to special teams, brings the head count to more than 100 games lost, your biggest problem isn’t your body of work. . . it’s keeping bodies healthy.

To be fair, the Steelers’ second- and third-team guys didn’t always play up to what Mike Tomlin labels “the standard.” But Pittsburgh was getting pretty deep into its roster when it started a fourth-team rookie tight end and a third-team rookie right offensive tackle who was among the final few selections in last April’s draft -- as a guard-center. David Paulson? Kelvin Beachum? Who were these guys?

That’s the NFL, though. There’s no guarantee of good depth or health. That’s why Tomlin preaches “the standard is the standard,” and never drafts shamans, witch doctors or Dr. Oz.

Another fleet receiver, if Mike Wallace departs as expected, and maybe speed for the aging defensive front seven would be nice additions, though. Pittsburgh needs to restore its pass rush, the missing ingredient in causing more turnovers than the franchise-low for a 14- or 16-game season, with 10 interceptions.

And maybe, while they’re at it, the Steelers should add some younger offensive linemen because the current ones continuously get hurt, as Willie Colon has played in 12 games the past three seasons combined.

Free agents who must be signed:

  • G Ramon Foster -- He is the new Max Starks, the offensive lineman whom the Steelers just cannot pry from their starting lineup. Starks, after back-to-back years where they ultimately came back to him out of necessity, probably has played his last game with the Steelers. Unless, of course, Pittsburgh tackles keep getting hurt, as they have been wont to do.
  • CB Keenan Lewis -- He may give them their best second cornerback, opposite Ike Taylor, since. . . wow, some of Rod Woodson’s sidekicks 20-plus years ago? But in a pass-happy league, Lewis may have priced himself out of the Steelers' range with more than $10 million that must be excised from its cap.
  • G Colon and OLB James Harrison -- They are not free agents, but they are veterans with contracts that must be redone for the Steelers to get under the cap and compete for Lewis, Foster and more. Colon could be released and re-signed. Harrison has a $10 million cap hit next season, and while he finished with a flourish that resembled his old self, Pittsburgh cannot afford to pay him the value of a 2007 Harrison. This list leaves out WR Wallace, who is a No. 2 receiver who wants No. 1 money, and RB Rashard Mendenhall.

Positions needing improvement:

  • Offensive tackle -- If Marcus Gilbert moves over to left tackle and stays healthy, he might be a pretty option to supplant Starks. But rookie Mike Adams, before he got hurt, didn’t prove himself as a capable pass blocker at right tackle.
  • Defensive line -- Especially if NT Casey Hampton exits as expected, Steve McLendon, a restricted free agent, figures to fill the void. But help will be needed there. Neither Ziggy Hood nor Cameron Heyward have transformed into anything more than a functional defensive end, and somebody there needs to border on Pro Bowl level for the line to perform at its best. Pittsburgh ranked around the middle (No. 15) in NFL sacks and near the end (No. 22) in quarterback hits. Is there a burgeoning star defensive lineman available around No. 17 in the draft?
  • Wide receiver -- Antonio Brown, when healthy, can be a decent No. 1 receiver. But in the absence of Wallace, Emmanuel Sanders isn’t quite up to the No. 2 bill. So fresh legs -- and, of course, hands -- must be found. 

Follow Steelers reporter Chuck Finder on Twitter @CBSSteelers and @cfinder.