Manchester United will be walking into a cauldron of noise when they enter Donbass Arena for their UEFA Champions League match against Shakhtar Donetsk today. Donetsk has never lost at home to an English team in the Champions League and their manager, Mircea Lucescu, has already started the mind games with Manchester United.

The veteran of 109 Champions League matches used his pre-match press conference to say this about Moyes and his current team selection:

“There will always be a change of philosophy under a new coach and every coach needs time to work in a proper way. This is why David Moyes is facing difficulties at this stage. But we have analyzed the United games and we noticed there are always changes in the squad, maybe four or five players [in each game].

“This rotation means the links between the players can be affected and I think turnover can cause a lot of problems sometimes. We have also discovered that here. The other big teams in the English championship, such as Chelsea, Liverpool and Arsenal, are not rotating the team as much as United and maybe that is a factor. We know the work of Mr Moyes from Everton and he is one of the strongest coaches in the Premier League. He needs some time to work with his players and let’s hope the team finds a good pattern after [tonight].”

Lucescu is playing mind games with Manchester United. In the past, it was United who took advantage of these situations, to play mind games with opposing managers. But now it seems the tables have turned.

For the first time in recent memory, Manchester United’s fear factor over their opponents has taken a hit. West Bromwich Albion dealt the Red Devils’ aura of invulnerability a huge blow when they walked into Old Trafford and beat Manchester United, 2-1.

For United to lose at home may not seem like a big deal. But take the manner in which they lost.

United had gone behind 1-0 in the second half, but had scored one of their trademark home goals just three minutes later to level the match. In the past, as Manchester United supporters know, this is the point where their club usually kicks off. As described by former Red Devil Gary Neville on Sky Sports Monday Night Football, “What you’ve always seen Manchester United teams do from that point on is: get after teams, chase the ball down, create loads of chances. Honestly that was the most disappointing thing. The period between United scoring and, if you like, West Brom scoring the second [goal]. It’s an incredible passage of play.” He went on to describe United’s effort and execution as “surprising” and “disappointing”. The Red Devils did not look like themselves and they definitely didn’t look like the Champions of England.

That passage of time was the defining moment in the match. What United need to do in the Ukraine is make sure they don’t let that be the defining moment of their season.

Of course you will hear that it’s still very early in the season for anything to be considered a “defining moment”. But that’s not the case. Defining moments take place all the time. At any time, a moment can change the fortunes of a player or a team, for better or for worse.

One of last season’s defining moments affected two teams simultaneously. It was the moment at the Etihad when Robin Van Persie stepped up to take a free kick against Manchester City with the scores level in the dying moments of the game. As his free kicked sailed towards the Manchester City wall, instead of staying square to the ball and allowing it to hit him, Samir Nasri turned his body away from the ball and stuck out a limp leg. The ball glanced off his leg, changing its course just enough to fall past the diving Joe Hart and United won the match, 3-2.

Yes, it was an early season match between the two clubs and there were still 30+ games to go in the season. But that display by Nasri deflated a City team who had battled back from a two-goal deficit to level the match. Most fans can still remember Pablo Zabaleta running down the pitch, urging his teammates to win the match after he scored the tying goal with eight minutes remaining. Then, only minutes later, viewers see him leaning against his own goal, deflated, after watching Van Persie’s free kick sail by Joe Hart. Nasri’s effort and Zabaleta’s face provided a window into the mentality of the Manchester City team for that season.

As that season progressed, and Manchester City began to unravel, the manager and his players would admit that they had become complacent after winning the title the year before. Roberto Mancini and Joe Hart were not shy about admitting it. They weren’t the same team mentally. They weren’t ready to fight and scrap until the last second to win a match. Zabaleta recently gave an interview admitting that he and his teammates failed to live up to expectations after winning the title. Nasri’s moment during the Manchester derby truly defined the team that season.

That moment also sent United off and running. Their confidence was sky high. They had exorcised the demons from the year before with the win and never looked back in winning the title last year.

During the 2011-12 season, the one that saw Manchester City win the league on the last day of the season, it could be argued that Manchester United’s defining moment was on April 11, 2012 at Wigan.

Prior to the match, United had a safe lead over Manchester City in the league table. The talk amongst supporters and most experts was: “After United beat Wigan, they’ll clinch their 20th league title on the following Sunday with another win… once everything falls the way it’s predicted.”

But a funny thing happened to the Red Devils. Wigan completely outplayed them that day. Shaun Maloney scored to give Wigan a lead they never relinquished. That loss led to a stumble, a brief slip in United’s season. That slip gave Manchester City an opportunity to close the gap between the two clubs. Then a few weeks later, City and United were tied on points. We all know what happened after that. (AGUEROOOOOO!)

Last season, Manchester United’s Champions League campaign was defined in the moments following Nani’s controversial red card against Real Madrid. With United down to 10-men and nursing a one-goal lead, Real Madrid went on to score two goals in quick succession to effectively end United’s pursuit of a Champions League title.

United’s failure to compose themselves during the minutes following Nani’s dismissal cost them dearly. After Madrid’s second goal went in, United came back to life, but couldn’t get the necessary goals to advance.

Prior to the match, Sir Alex Ferguson had been hailing his United team as the deepest squad since his 1999 treble-winning team. A poor display during a 10 minute period of the match against Madrid ended that team’s Champions League season.

Defining moments happen all the time, and at any time.

For United and Moyes there is no escape from the scrutiny accompanying the worst start to a season in 24 years. But, during his press conference appearance in Ukraine, Moyes repeated his belief that he will restore United’s fortunes.

“I’ve been in situations similar to this at Everton and Preston North End,” he said. “You get on with it, you do the right things and you carry on. The results will come, there’s no doubt about that.”

The moment of truth for Manchester United will be when they step out on the Ukrainian pitch in front of 50,000 screaming Shakhtar Donetsk supporters. The cauldron will be bubbling. They will be facing a team that has never lost to an English team on their home ground and senses weakness in their opponent.

The question is: How will this United team define themselves in that moment?