Lets get some perspective here, flat performance it may have been but this was a game we knew we didn't have to win before kickoff. Some may argue that's two poor performances back to back, but we got the outcomes we wanted from both games.
We needed 3 points and deserved to get them in the end on chances created at the weekend, we probably only deserved a draw at best tonight(you're not telling me they played expansive football as BT tried to make out) but we have guaranteed top spot with that result tonight. Under Pep, CL performances anywhere near that flat are few and far between, some of our very best performances come in that competition in fact.
Pep did say the players were tired after Saturdays game and needed an extra days rest. I can't remember a team in the PL that has entertained, played with such high intensity and won so many games without any compromise for 2 seasons straight(it's usually win at all costs "the sign of champions tm"). I think Pep is having to put out fires in too many places at the moment, injuries, unable to play a consistent back 4, fatigue(possibly linked to the past two seasons), players out of form, the teams press deteriorating as a result of the former issues raised.
It stands to reason there's only so much Pep can do to stop injuries, other than try an make sure fatigue isn't a big factor. The answer for fatigue is to rest more train less, but that comes with it's side effects I would have thought. I think if they are fatigued, we should rest them as much as we can before the fixtures really start to pile up. The way some go on in the match threads, they think the players have infinite reserves, they'd burn them out by September.