There is no shame in Arsenal losing to Bayern Munich as they did on Tuesday night. The Bavarian giants are running away with the Bundesliga and are the favourites to win the Champions League after Barcelona lost at AC Milan on Wednesday.
What isn't acceptable is the manner in which Arsenal lost at Emirates Stadium. And, because of how Arsene Wenger's players approached the game, they only have themselves to blame.
I don't particularly blame Arsenal or Wenger for their defeat against Blackburn at the weekend. It came at an unfortunate time, and now and again bigger sides do get beat by lower-league opposition. You only have to look at Bradford City's run in the League Cup this season or Leeds United's victory at Old Trafford against Manchester United a few seasons ago to realise that it can happen.
However, there was an unforgivable lack of desire and effort shown by numerous members of Wenger's side during spells of their game against Bayern Munich.
Arsenal didn't need to put on an incredible tactical show in order to stifle Bayern's attacking threat. What they did need to display was the attitude and desire of a Sunday league footballer. And at times, particularly in the first half, they didn't.
It left me thinking, for the first time under Wenger's spell at the club, two things. Firstly, are the players really playing for the manager? And secondly, do they have the desire to represent the club and fans in the manner so many previous Arsenal sides (successful and not so successful) have?
If the answer to both questions is yes, then Wenger needs to adapt how he approaches games because his side are no longer good enough to simply turn up and beat the opposition on account of them being better than them.
To highlight my above concerns you only have to look at the first two goals Arsenal conceded in their 3-1 defeat to Bayern.
1-0 Bayern, Kroos: Laurent Koscielny received the ball from Per Mertesacker and for want of a better word hoofed the ball forward. He came under a little bit of pressure but elected to hit it long. No problem with that. What was surprising, was that Arsenal's midfielders on the night (Santi Cazorla, Mikel Arteta, Jack Wilshere and Aaron Ramsey) didn't come short or provide an option for the Frenchman to pass too.
Other than pass back to Wojciech Szczesny there was very little Koscielny could do. It meant that straight away at least four Arsenal players hadn't done their job. How can you expect to compete in a game of football let alone a Champions League game if you don't want the ball? Mistake number one.
Mistake number two and more damaging was the lack of desire shown by the Arsenal midfield to track back and chase the ball once they had lost possession. By the time they had trotted back into position Bayern had broken down the right, the ball had broken to Kroos on the edge of the box, and he had dispatched past Szczesny.
It was a good goal but could have been prevented 10-15 seconds earlier if, at the very least, Arsenal's midfield had got goalside quicker. If you manage to catch the goal again, take a look at Cazorla's laboured attempt to get back in. You don't need a coaching badge to know that getting men behind the ball quickly when you lose possession is one of the first steps a side should take when attempting to regain the ball. In short, bust a gut, get back in.
2-0 Bayern, Muller: Defending a simple corner. It wasn't like the Stoke City corner that caught West Ham out earlier in the season; Mertesacker and Koscielny were simply caught sleeping and didn't win the first header. No sooner had Szczesny palmed Daniel Van Buyten's free header out, Thomas Muller had converted from three yards. It may have been acceptable if Van Buyten had to fight to win the ball, but he didn't, he crouched to flick it towards goal under no pressure, and Muller's task was easy.
Again, it was down to concentration at a set piece and not carrying out the basics from the training ground. Arsenal's defenders were slow to react and the second goal meant that Bayern were almost out of sight.
I haven't mentioned Mario Mandzukic's free header later on in the first half or Bayern's third goal courtesy of the Croatian international because you could argue that Arsenal were pressing on in search of a goal themselves at that point, and the inevitable gaps were appearing at the back. Both Mandzukic's chance and the third goal, though, did highlight further defensive shortcomings from other members of Arsenal's side.
24 hours later in Italy, AC Milan entertained Barcelona at the San Siro in one of the ties of the Champions League knockout stage.
On paper you could argue AC Milan's side isn't that much better than Arsenal's, if at all. What AC Milan did, though, was adapt their approach to suit the game and opposition.
They tried to make the pitch as narrow as possible and defended their 18 yard box not only with tactical discipline but with a determination and a willingness to get the job done. Without such a desire (yes the sort you might see on parks this weekend) AC Milan's plan wouldn't have succeeded.
And the result? A 2-0 home victory against Barcelona with the goals scored by former Portsmouth players Sulley Muntari and Kevin-Price Boateng.
Arsenal players - take note.
You can find Tom on Twitter at @FootballMcD.