In particular, the availability (or not) of KDB had nothing to do with our loss against Spurs. Watch Pep's post match interview and listen to what he had to say on the subject.
We lost against Spurs because our pivot in the first half was so awful that we could not build play from the back and because we had no defensive cover. Stones/Otters/Zabba/Kolarov were under huge pressure in the first half with no help from our pivot - each of these players made errors, big errors; two of those errors (Zabba for the first, Otters and Fernando for the 2nd), led to goals from the opposition. And several other dangerous situations arose as well due to extremely poor play from Fernando - we were bailed out by offsides or by very poor decision making on the part of the attacker three or more times more in the first half.