The Steelers can only roster 53 players, and the lower men on the totem pole are constantly fighting for their spots every week.

This week, the Steelers prized free agent acquisition this offseason, tight end Ladarius Green, started practicing. Pittsburgh has 21 days to decide whether to activate Green, promoting him from the PUP list to the 53-man roster, or he must remain on the PUP list for the remainder of the year.

Inevitably, a player currently on the 53-man roster must be released to make room for Green. Here’s a list of players who could be on the chopping block.

Shamarko Thomas

Drafted in the 4th round of the 2013 NFL Draft, Thomas has never lived up to his potential billing: a replacement for Troy Polamalu.

Worse, Thomas has seen every opportunity to take the torch, and become the Steelers starting strong safety, fall short. Thomas also lost his job to a longtime special teamer Robert Golden, 2nd round rookie Sean Davis, and on/off practice squad longshot Jordan Dangerfield, over the course of the last two seasons.

Now relegated to special teams play, Thomas has been injured over the last few weeks, and may have even lost his spot in that capacity.

If the Steelers like what they see with him off the field, Thomas could be cut to give way for Green.

B.J. Finney

I’m going to make this down as unlikely, but with the Steelers offensive line coming back to full strength, including Marcus Gilbert and Cody Wallace, Finney could end up being the odd man out.

However, Finney’s play, combined with making the final 53, more than ensures he’ll remain on the roster.

Xavier Grimble & David Johnson

Logically, one would think a tight end might get cut to make way for another tight end. Both Grimble and Johnson could be on the chopping block.

Grimble has seen more snaps than Johnson, but has had some costly drops in games this season. Originally a long shot to make the roster, Grimble was likely retained in spite of Green’s injury. If the Steelers feel that Grimble has hit his ceiling, he could be gone.

Likewise, Johnson has to compete with the returning Roosevelt Nix, who plays a similar role in the Steelers offense. Last season, Pittsburgh retained 2 fullbacks and 3 tight ends: they currently have 2 tight ends (Jesse James, Grimble) and 2 fullbacks (Johnson, Nix) which may mean both players’ spots are safe.

Cobi Hamilton

Recently called up from the practice squad due to a number of injuries to wide receivers, Hamilton may also find his role to be obsolete with players returning from injury. Both Markus Wheaton and Sammie Coates are expected to be back after the bye, leaving Pittsburgh with 6 receivers on the 53: Hamilton, Coates, Wheaton, Antonio Brown, Darrius Heyward-Bey and Eli Rogers.

For that reason alone, Cobi could be moved for Green.

Steven Johnson

Johnson was a roster casualty during the final preseason cuts, but was resigned to the 53 man roster when the team placed LB Bud Dupree on Injured Reserve.

I have a gut feeling Johnson could be moved, but not for Green: he has shown to be valuable on special teams, and was responsible for a forced fumble during a punt return in the New England game.

If Johnson is released, it’s likely it could happen when Dupree returns.

Cody Wallace

Wallace, who plays guard and center, has the most value as a Maurkice Pouncey‘s backup; a job he did for every game in 2015. However, Wallace has yet to play a single snap in 2016, and with the emergence of B.J. Finney, I wonder if he may become expendable?

Brian Mihalik

Waived in August because of an injury, Mihalik returned to the Steelers on October 18th, signed directly to the team’s active roster to provide depth at the tackle position.

With Marcus Gilbert returning to 100% health, Mihalik might be the lowest man on the totem pole, if the coaching staff feels that other players are more valuable.

My educated guess is that Mihalik’s job may only be safe if the team feels they need someone behind Chris Hubbard, if Gilbert isn’t quite in full form.