Yeah, it probably won't happen. But I still think that his decision was small time and short sighted, especially since it's only Villa at the weekend.
Even at half time he could've made some adjustments, like for example bringing on Dembele to strengthen the midfield - at that time it was still just 1-0. Instead he waits until an hour has passed before Dembele gets subbed in for Chadli and then he subs in Lamela and Kane for Eriksen and Son after the game is basically already over. And to achieve what exactly? Sight seeing? If you want to rest players then leave them on the bench, if you want to get something out of the tie, then don't wait until it's 0:2 or 0:3 before you bring on the better players!?
And what message does it send? Most of their players probably see Spurs as a stepping stone towards bigger clubs. Proving themselves against big(ger) European sides is probably precisely why they joined the club and then Poch tells them: feck that there is not enough money in it? feck competing for silverware, when there is not enough money in it? feck the supporters who traveled to Germany? feck the supporters who bought expensive tickets for the return leg?
Most teams who are new to the CL struggle with the pressure and level of competition in their first season, so this would've been a chance to introduce that kind of atmosphere to the team, so they wouldn't be as naive and green when they get to play it next season. And on top of that I expect that on some level such a schooling will affect the team's confidence and momentum.
I'll reply to the Dortmund bit specifically because the rest is just the typical bluster dressed up as 'banter'.
There has been a lot said about the selection that night (including, by way of disclaimer, me too).
However, if we actually want to look at what Poch ended up doing.
The back 5 were first choice. Rose and Vertonghen were injured. You could argue that Walker is nominally first choice over Trippier but Poch has been rotating the fullbacks at will.
For the midfield, Dier had a knock and so didn't travel. Dembele had only just returned from injury days previously and Poch tends to return players back from injury slowly. Alli was suspended. I'd perhaps have played Bentaleb over Carroll but Bentaleb has been a bit of a dick this season so not incredibly surprising that Poch didn't want to go for him.
The front four is certainly where you can argue a bit more. I would have started Lamela and Kane. Personally. But I can see why he didn't. Especially as Son knows Dortmund and has had quite a good record against them.
So when it comes down to it, all of the anger, disappointment etc, over....what? Kane and Lamela and a not yet fully fit Dembele? Really?
As for a few of the other points that people have been making:
It is 'just Aston Villa'.
Really? Just...really? Is this the same Aston Villa who held the team currently 5 points clear in 1st to a draw just a few weeks back? Or the crap Norwich who held Man City to a draw last weekend? Or the weird points that every single team has dropped so far this season against so called inferior or crap teams?
'We should be good enough to compete for both, especially if we want to be called title challengers'.
Currently, the team top of the league and the favourites for the league aren't in any European competition. They exited both of the domestic cups early. Are they gonna care about any of that stuff for one second if they win the league?
We are also not just competing for the league but competing against the teams below us too and trying to hold them off. Dortmund are 5 points from the top like us. But they're 16 points clear of the 3rd placed team and 20 clear of 5th place. We're 6 points off 3rd and 9 off 5th, with all of the teams below having a game in hand.
And where has this come from anyway? How many of you, who suddenly consider us good enough to be both title challengers and go toe to toe against one of the best teams in Europe thought we'd even be in the top 4 this season? How many of you would have laughed at Glaston if he'd suggested that we'd possibly finish in the top 4, let alone possibly ahead of Chelsea, Liverpool, Man Utd, Man City, Arsenal? And now suddenly we should be good enough to be realistic title challengers and also be competing well for the EL too? Have we entered an (admittedly very pleasant) alternate universe where Spurs are consistent title challengers with squads that regularly win FA cups, Europa leagues, Champion leagues etc on top of the leagues we win?
How often do we win the league? How often do we challenge for the league? How often can we actually realistically, objectively say that we have more chance of winning the league than any of the other trophies?
As for two poor teams, if the league had started on 1st December, Bournemouth would be 3rd in the table. We're not a good enough team to just have games where we know 100% we're going to win and can rotate the team wholesale and it not be a problem.
Beating Dortmund
For me, Dortmund are one of the top 5 teams in Europe, at worst a top 10 team. Even with a full strength team playing at our best, I'd give us a chance of going through perhaps only 2-3 times/10 against Dortmund. Then we have another few rounds, in a cup competition where things can always come down to a single mistake by a player or ref. We had more chance of winning the league then the EL, especially once we got drawn against the clear favourites.
I'd have preferred Poch to play a slightly stronger team. However, due to injuries, the team wasnt as bad as it initially appeared. And it isn't illogical to prioritise the league currently, considering we are both in a challenge for the title.