3 Pittsburgh Steelers most to blame for stunning upset loss to Colts and Joe Flacco

The Pittsburgh Steelers started the season on a three-game win streak despite injuries to Russell Wilson and half of their offensive line. Eventually, those absences were doing to catch up with them. The reaper came calling on Sunday, when Pittsburgh fell to the Indianapolis Colts at Lucas Oil Stadium. Should the Steelers have won this game? Absolutely. Could they afford a loss here or there given their multi-game edge on the AFC North? I guess.

Nonetheless, the Steelers offense did just about all Arthur Smith could ask of them in the second half, and had a chance to win late. Penalties on the offensive line ultimately doomed them, along with a sorry defensive display against Colts backup quarterback Joe Flacco.

Mike Tomlin teams tend to play up and down to their competition. There is no in between, and though I wish I could say we saw this coming, Steelers fans never do. It's why they react in such outrage every time Pittsburgh falls short against a team they should've beat. By no means is this article a slight at the Colts, but the Steelers were favored to win this game with Anthony Richardson as the expected Indianapolis starter. With Flacco in, surely Pittsburgh should've made a stop or two prior to the last Colts drive of the game.

Okay, perhaps I'm getting ahead of myself slightly. There is plenty of blame to go around for a Steelers team that waited just a bit too long to remember they had a football game today.

3. Najee Harris and the run game failed the Steelers

Najee Harris needed to have a big week for Pittsburgh to win in Indianapolis. The Steelers run game hasn't been as productive as they would've hoped so far this season. Justin Fields was the exception there, and added two more rushing scores to his name from the quarterback position on Sunday. Fields cannot be the bell-cow of the Steelers rushing attack. He needs Harris -- who is likely in a contract year, by the way -- to pull his weight.

Rather, Najee had just 19 yards on 13 carries against the Colts defense. He came into Week 4 averaging just 3.8 yards per carry, and that will go down again this week, proving once and for all just how much Pittsburgh needs a healthy Jaylen Warren.

Harris wants to be paid like a No. 1 back, but he's done little in the past year to separate himself from Warren and the rest of the Steelers rushing attack. Sunday's game won't help that perception

2. Mike Tomlin failed again in a game Steelers should've won

It's early in the season, sure, but I feel fairly certain that the Colts are not a playoff team, at least not as currently assembled. Indianapolis' first-string quarterback went down, and Tomlin let an old enemy in Flacco tear one of the best defenses in the NFL apart. Sure, most of that is not on Tomlin but the unit he and Omar Khan have assembled. But this is a pattern for Tomlin-coached teams. The minute Steelers fans get comfortable, the teams comes crashing back down to earth.

Tomlin will not go scorched earth on his team, either. He will blame penalties, missed tackles, turnovers and poor execution, rather than discussing X's and O's with the media. It has always been his way, and it's what makes Tomlin infuriating to the fanbase and beloved by players. He handles any and all adjustments in-house.

The Steelers placed too much pressure on their young quarterback to make a stunning comeback in the second half. He had 367 yards of total offense, but little help around him. Turnovers and penalties didn't help, but the Steelers coaching staff didn't adequately prepare the team for a game they should've won. Or worse, they did and it didn't matter.

1. The best defense in the NFL didn't show up on Sunday

The Steelers didn't do their defense any favors thanks to a few uncharacteristic turnovers, but TJ Watt, Minkah Fitzpatrick, Cameron Heyward and Co. are supposed to be better than this. Patrick Queen and Joey Porter Jr. are better than this. Young quarterbacks like Richardson and backups like Flacco are traditionally where the Steelers defense feasts. This should've been a far more convincing box score in Pittsburgh's direction than it was.

The Steelers gave up just under 400 yards of total offense to Richardson and Flacco. Jonathan Taylor gashed them for over four yards-per-carry, even though anyone with half a brain knew that was coming pregame. The Colts offensive line won the line of scrimmage. And, perhaps worst of all, the Steelers failed to cash in several critical third-and-longs, thus keeping a tired defense on the field to the point of exhaustion and, eventually, touchdowns scored by Indianapolis.

Richardson is turnover-prone and Flacco is a shell of his former self. He should not shred the best defense in the NFL (or so-called) entering Week 4. The Steelers defense fell asleep at the wheel, and it showed.