|Champions League third qualifying round, first leg: Celtic v Qarabag|
|Venue: Celtic Park, Glasgow Date: Wednesday 29 July Kick-off: 19:45 BST|
|Coverage: BBC Radio Scotland 810 MW (no online rights), live text on BBC Sport website|
Celtic Park has a hard-earned and well-deserved reputation for hitting decibel levels that could raise the dead on big European nights.
The supporters' capacity to inspire the players was something that John Collins, Celtic's assistant manager, spoke about the other day.
He mentioned that, when Qarabag, the unglamorous but dangerous champions of Azerbaijan, fetch up at Parkhead on Wednesday evening for a Champions League third-round qualifier, there will be knocking on for 40,000 Celtic fans waiting for them. It could be the biggest crowd in Champions League football this week.
A terrific atmosphere is guaranteed, a decent result far less so. When we talk about Celtic Park being a fortress, we have to go back further and further in time to back up the argument. Most recently, the raucousness has rarely been matched by the result.
Since their last home European victory against an established power - Ajax in October 2013 - Celtic have lost 3-0 to AC Milan, 3-1 to Red Bull Salzburg, 1-0 to Maribor and drawn 3-3 with Inter Milan. Ten goals conceded in four winless games in their citadel of old.
The two notable games that they won - 1-0 against Dinamo Zagreb and 2-1 against Astra Giurgiu in last season's Europa League - were both anxious and error-strewn affairs. You credited Celtic for showing the character to pull themselves out of a hole, but those were performances that didn't so much quicken the pulse as trouble the heart.
Ronny Deila's team could do with a thunderous night on Wednesday, for if their opponents lack familiarity then they're not short on threat. The truth is that, even though your ordinary Celtic fan would struggle to name a single one of their players, Qarabag's record in Europe last season demands respect.
This time last year, they played Salzburg in the Champions League qualifiers and lost 3-2 on aggregate. Celtic later lost their own head-to-head with Salzburg 5-3.
In the Europa League, Qarabag went to Kiev and beat Dnipro, the eventual Europa League finalists. They drew twice with Saint Etienne and once with Inter Milan. They don't win many matches in Europe, but they don't lose too may either. They're nuggety - the type of team that Celtic could have a real problem with.
Qarabag have had a fair old turnover in players in the summer, but five, six, or possibly seven of the team that beat Dnipro are likely to start against Celtic. The bookmakers have the Azerbaijans as huge underdogs, but it's hard to see where that logic comes from. There's not nearly enough evidence of Celtic's quality to suggest that this is going to be routine.
It's hard to make a bold call on where Celtic are at right now. Mikael Lustig is back in the defence - he wasn't around for much of last season - and that's a plus. Dedryck Boyota has replaced Jason Denayer as Virgil van Dijk's centre-back partner and Boyota looks a fine acquisition.
Gary Mackay-Steven and Stuart Armstrong have had half a playing season and a full pre-season to settle into Celtic's ways and they're both looking good. When you throw in the burgeoning Scott Brown-Nir Biton partnership and the effective Stefan Johansen - five goals in 16 European matches for Celtic - then the gut feeling is that Celtic are in better shape now than when they were beaten by Legia Warsaw, Maribor and Salzburg.
Until we see them in a game of proper intensity and against opponents with clever attackers then we can't know for sure, though.
An area of uncertainty is up front. Celtic's three principal strikers in the squad for the qualifying games with Stjarnan were Nadir Ciftci, Leigh Griffiths and Anthony Stokes, who, between them, have played 33 European matches for Celtic and have come up with the princely total of one goal.
Stokes, of course, accounts for the bulk of that number- 23 goal-less European games as opposed to Ciftci's two - but it's an issue for Celtic. The now departed John Guidetti had a ridiculously high opinion of himself last season, but the reality is that he played a total of 74 minutes of European football for Celtic - against Inter Milan - and he managed to score.
Celtic still lack a predator that can do damage in games like this and the ones that may lay ahead. They'll be banking on Johansen, Mackay-Steven and Armstrong to weigh-in and, in fairness, the three of them are well capable. But is Ciftci the solution as the chief striker? His track record suggests not, though he's young and capable of improvement.
He might be many things - a physical threat and a creator - but what Celtic need most, and have needed for some years, is a dependable goalscorer to rescue them when they're not at their best in Europe. Those guys tend to cost the kind of cash that Celtic can't countenance, especially if they're locked outside the great money-fest that is the Champions League for the second year running.
Celtic live in an upside-down world where their most meaningful games, like Qarabag, come right at the start of the season as opposed to the end. Their bread and butter is the domestic league, but the jam only comes if they qualify for the Champions League.
So Celtic Park will be loud on Wednesday. Loud and expectant, but nervy too.
Victory against Qarabag over two legs gives them a shot of the play-off and a vision of financial and footballing nirvana. Most Celtic fans are too gnarled to look too far down that road. That's the message from Deila and it's one to heed.