The Ravens need to win this weekend to keep their playoff hopes alive, but that is not the only mountain they need to conquer.
With the Pittsburgh Steelers coming to M&T Bank Stadium on Sunday, the Ravens need to vanquish the specter of a three-game losing streak at the hands of their AFC North competition, one that includes a heartbreaking loss in last year's AFC Championship.
Only a part of what is perhaps the NFL's best rivalries – it is certainly the most physical battle every year – Harbaugh feels like a seasoned Ravens/Steelers professional.
"After having been in it for three games, I feel like I've been in for a lifetime – after last year," the coach said. "Obviously, they've got a little bit of an edge on us so far in that span, so we've got our work cut out for us."
Middling at 5-5 among a pack of teams that have their eyes on a Wild Card berth, the Ravens have made no secret about the fact that it is a one-game season from this point on.
The Steelers, who own a 16-10 advantage in the regular-season series, are essentially in the same situation. They have a 6-4 record and a two-game losing slide, looking up at the division-leading Cincinnati Bengals.
"I think this year it's really important right now because we're a 5-5 football team, and they're a 6-4 football team," Flacco explained. "Whoever wins this game is right in the middle of things."
"We need to win this game, and I think that's what we need to go out there and make our goal on Sunday."
Flacco needs the win just as much as his teammates, and without Pittsburgh safety Troy Polamalu, who will not play due to a knee injury, those chances are slightly escalated.
The Steelers' defense has gradually answered anything Flacco was able to do to them last year.
In three meetings, the Steelers sacked Flacco 10 times, snared five interceptions and forced his passer rating to plummet with each game. Flacco earned an 81.7 mark in the first loss in overtime, 22.2 for the second regular-season meeting and 18.2 in the playoffs.
"We played them well the first game and lost," Flacco said. "Played them well the second game and lost. Played them somewhat good the third game – we didn't play great – but we came back at the end and gave it up there. They're a tough team. We've played a lot of games this year that have been tough games and close games, and we haven't come out on the right side of any. We didn't come out on the right side of any against those guys last year.
"Eventually, we're going to have to learn from those situations. I think this game coming up and the next six games we have left, I think all those tight games are going to help us fight through those situations if they present themselves again."
The Ravens know they are in for a slug-fest, given the current circumstances and previous history.
It seems that each showdown features one or two devastating hits that can set a frenzied crowd even more ablaze.
In 2006, linebacker Bart Scott, now with the New York Jets, notched what might have been the highlight of the season when he de-cleated Steelers quarterback Ben Roethlisberger on an untouched sack. Pittsburgh safety Ryan Clark returned the favor in the AFC Championship with a high shot to Willis McGahee that briefly knocked the running back unconscious and sent him to the hospital.
Such physicality is why the Ravens' defense also takes responsibility whenever the Steelers are on the opposite sideline.
"Now the two teams clash because we're very similar in styles and the way we play defense and things like that," said linebacker Ray Lewis. "That's what makes it a very physical game because we know the way their defense is going to play, and ultimately, it's going to come down to one of our defenses making a play."
Whether it is Flacco or the Ravens' defense, someone in purple and black needs to make a game-changing play if Baltimore wants to get over the roadblock the Steelers have recently built.
For many of the players, both old and young, the past between the Ravens and the Steelers feels like something they've lived their entire lives.
"Here we go again," Lewis recalled. "Their tradition, their legacy, is respectful, so respectful. There are so many great ones that came through there, and that's why, honestly, if you want to know why I always try to give them my best game, [it is] because I know all of the great Pittsburgh Hall of Famers are watching.
"I know all of them are dialed in. I know how many Pittsburgh fans are out there, all of that good stuff. [I feel] like, 'OK, if that's what you want to see, let's go at it.' I think it's just a final respect for the organization and their legacy and definitely the way the guys they have on their team uphold it."
Running back Ray Rice, who is in his second season, summed it up more succinctly.
"If you're in black and gold, and we're out here in purple and black – that's just not a good mix."