The question is, how much?
No one is accusing Johnson of being an elite-level player, but the best asset he had is position flexibility. He was very likely to be the starting fullback, along with the team's third tight end. So as the team loses Johnson, the likely result will be the necessity of keeping his replacement as well as another player to fill his other position.
Who will those players be?
Ideally, Steelers coach Mike Tomlin will not want to use a deep roster spot for both a fullback and a tight end if he doesn't have to. Since his powers of human motivation won't extend to David Johnson's knee, making it heal within the next two weeks, he may have to do that if no one can show the ability to be on the field for the Steelers' base offense at fullback and deeper formations as a tight end in the event of injury.
This all is predicated off TE Weslye Saunders' suspension, and whichever player is selected for that 3TE position could be the odd man out upon Saunders' return after the first four games.
Rookie Training Camp Darling Will "You'll See" Johnson looks to be the odds-on favorite for the fullback job, but he doesn't play tight end.
The Steelers have experimented with Jamie McCoy at fullback along with his usual tight end duties. Veteran Leonard Pope has tight end and H-back experience, which isn't exactly a fullback pedigree. The newly acquired Peelle has been a tight end and an H-back, but again, he hasn't been a pure fullback. Rookie 7th round pick David Pausen seems to have a future in the NFL, but word is that future won't include an active roster spot in 2012.
None of these players really showed anything newsworthy in the Steelers first preseason game, but they also clearly weren't a part of the passing game plan. The Steelers didn't run the ball particularly well, and that blame can be passed around to several offensive players.
Expect the second game to be much different. It's not as if Tomlin won't ultimately take the 53 guys who will help his team win on Sundays, but he isn't going to want to give a spot to anyone by default.
It's likely we'll see a combination of these players giving the fullback position a shot in practice and maybe as early as in Sunday's preseason home-opener against Indianapolis. Peelle's signing should serve as motivation for Pope, who was brought in to push David Johnson this offseason. McCoy and Paulsen are on the outside looking in, but could still make a few plays and get noticed.