There was never supposed to be so much riding on this game. That's partially due to the fact that it was originally supposed to take place in March, but more to the point it's because neither of these clubs looked to be candidates for a relegation battle coming into the season. Villa were weaker, sure, but they'd really seemed to gel down the stretch and ended the season in 9th. Bolton stumbled a bit at the end of the season, but considering the injury to talisman Stuart Holden that was almost to be expected. There weren't many that viewed either team as serious candidates for Europe, but the general consensus seemed to be that both would turn in respectable, mid-table performances.
From early on however, it was clear that things weren't going to go according to plan for Bolton. Winger Lee Chung-Yong suffered a broken leg in a pre-season friendly against Newport County, ruling him out for the season. Holden returned to the pitch in Bolton's 2-0 defeat of Aston Villa in the Carling Cup, but was shortly thereafter ruled out a further six months when a routine examination revealed what turned out to be damaged cartilage. Though it's difficult to speak of the loss of Fabrice Muamba from the team due to the upsetting nature of the events surrounding it, the impact of his absence is undeniable. And though these have been the most high-profile instances of attrition with which Owen Coyle has been forced to deal this season, there have been many, many others. You know the injury struggles Villa have been forced to deal with these past two seasons? Well, take those, combine them into one season, and multiply it by two.
As to how Villa has ended up where they are, well, there are differing theories. This isn't really the time or place for that discussion. What's important is the reality of things; what was once a pretty sizable cushion has dwindled to just five points thanks to a combination of draw after draw and the stubborn refusal of the teams below Villa to simply lie down and die. (Well, except for Wolves.) And depending upon the outcome of this game, Villa could go from being in danger of getting dragged into a relegation scrap to, well, being involved in a relegation scrap. Based on the point totals alone, Villa would still be favored to make it out alive and their schedule is favorable when compared to the clubs below them, but the remainder of the season would move from "nervy" to "terrifying" pretty quickly were the Trotters able to pull out a win.
For a lot of reasons though, a loss doesn't seem especially likely. As understandable as the circumstances that led to such a poor season may be, Bolton as currently composed is not a very good team. And though this has been a pretty terrible season for Villa, one thing they haven't done very often is lose to bad teams; the last team outside of the top six to beat Villa was Swansea City on January 2nd. Prior to that, Villa lost to Liverpool on December 18th and West Brom on October 22nd. Somewhat surprisingly for a team on the edges of the relegation battle, that's it; just three losses outside of the top six, and no losses to teams below 12th. It hasn't been games they shouldn't have lost that's hurt Villa this season, it's been a 1-1-9 record against the top six and, much more importantly, and inability to take full points from teams they should be expected to beat.
Turn two of those draws into losses and two into wins (which would give them 11, the same number as Sunderland and currently the second highest total in the league) and Villa is on 38 points and in a far more comfortable position. It's really not difficult to go back through individual games and mapping that scenario out, depressingly so. I don't actually believe that Alex McLeish goes into games against the likes of Wigan and Blackburn playing for the draw, but it's clear that the killer instinct is lacking; whether it's the players, the manager or some combination of the two, it's an issue.
It's an issue that there isn't time for, not now. Villa need to play as though they're down a goal until the final whistle blows, no matter the scoreline. They're just better when they're playing with a real sense of urgency; my theory is that it gives the young players less time to think about what they're doing and play based on instinct, but the why isn't all that important. The point is that things go all pear-shaped when Villa settles in to protect a lead, and this isn't really a game that gives them the luxury of blowing a lead.
Win here and the fears of the drop largely fade. With West Brom, a suddenly beatable-looking Spurs and Norwich City the remaining opponents, it might even set up a bit of streak that ends the season on a high note. Draw and Villa are in largely the same place they are right now, not especially convincing but at the very least poised to limp through the remainder of the season. Lose and the (perfectly legitimate) fears of a calamitous death spiral set in. Not to be overly dramatic, but this game is kind of a litmus test for how bad things can get. No pressure, boys.