Ready or not, here it comes:

• Once upon a time, not all that long ago, it was a unit being featured in every Jay Ajayi highlights package, as well as one that took part in the LeGarrette Blount resurrection tour. It was a unit that was one part of that whole accountability and discipline issue that cropped up during the four-game losing streak, and not in a good way.

• There has been some rough sledding for the Steelers defense through portions of this 2016 season, and particularly glaring were those instances when the run defense wasn't actually defending anything at all. Maybe because run defense has been one of the most consistent elements of this franchise since forever, when it was making Ajayi look like Walter Payton, that was a rather alarming development.

• Anyway, that was then. Today, the Steelers are 7-5 and their run defense has been a reason why they are on a three-game winning streak. And with a trip to Buffalo Saturday for a 1 p.m. game on Sunday, if the Steelers are to get to 8-5 it will because their run defense has made it four good performances in a row.

• The Bills are No. 1 in the NFL with 161.9 yards rushing per game, and No. 1 in the NFL with 5.4 yards per carry. LeSean McCoy has 949 yards rushing and nine touchdowns, and his 5.5 average is better than anybody else who's in the top 20. And two guys who aren't in the top 20 but have better averages than McCoy are Tyrod Taylor (6.4) and Mike Gillislee (5.9). Taylor is the Buffalo quarterback, and Gillislee is its fullback, and together they've added a dozen more rushing touchdowns to McCoy's nine.

• About McCoy, Coach Mike Tomlin said, "He is a great, natural runner. He has a great feel for the game. He doesn't run by numbers, if you will. He doesn't necessarily put the ball where it is supposed to go. He ad-libs at times. He is dynamic because of it. He challenges you to play assignment football because of that style of play."

• About Taylor, Tomlin said, "Tyrod Taylor is a big component of their run game as well, whether that is by design or ad-lib. They have some designed quarterback runs that are very challenging. They make you play assignment football."

• See where this is going? To defeat the Bills, the run defense is going to have to play big, and to play big it will have to play assignment football. Since assignment football is all about discipline and accountability, a victory on Sunday would represent significant in-season progress in an important phase of the game, a phase in which the Steelers had better be accomplished if they are to make the playoffs, let alone advance at all through them.

• It's Friday morning, and Randy Bullock is still on the roster, which means that he gets paid for Sunday's game whether he ends up doing the kicking or not. One of the long-time provisions of the Collective Bargaining Agreement calls for teams to pay a player for the upcoming game as long as he is on the roster through the middle of the week leading up to that game.

• It's decent money – an NFL game check – especially for a guy "on the circuit," as Mike Tomlin described the existence of unemployed specialists seeking employment in the NFL. "He's been around the block a little bit, a guy who's continually in the fold, meaning he's getting workouts, he's in the system," said Tomlin about Bullock. "That speaks to their overall readiness. It's not necessarily getting off the couch, per se. He kicked some this year. He was continually on the workout circuit, so that aides you in terms of the decision. You know, or at least you have a feel for his mentality and his physical readiness."

• And "the circuit" often contains the same group of people, be them placekickers or punters or even long-snappers, because during a tryout where one job might be available, the team conducting the tryout wants to put the candidates into the position of having to compete, which helps determine how they might respond to pressure.

• During the run-up to the game against the Indianapolis Colts, the Steelers were faced with the reality of beginning their preparation without knowing whether Andrew Luck or Scott Tolzien was going to start at quarterback. This situation was exacerbated by the game being on a Thursday night, which meant the planning had to happen on Monday, with the one real day of practice on Tuesday, followed by getting on an airplane to Indianapolis on Wednesday.

• Tomlin talked about how the Steelers handled that and why teams routinely expect the starter to play in all scenarios, except those in which the guy officially has been ruled out of the game: "More times than not, you better be ready to see the starter. Although we heard the things you guys heard regarding the concussion protocol with Andrew Luck, we still better do our due diligence in terms of being ready to see him. Then if we don't see him, we make adjustments accordingly. What you don't want to be is on the other side of that equation – anticipating a backup and Andrew Luck steps out of the phone booth with a cape on. We're going to be prepared to see Andrew Luck, and then we'll adjust accordingly."

• By the way, Bullock's single-game check, based on his years of service in the NFL, comes to $39,705.88.