I don't think any eventual winner goes through a season without this sort of spell, the main thing is we don't know when we're beaten, we just drive on and on regardless and that's why we've mustered a few points when we've arguably not deserved it and I think that will stand us in good stead.
We definitely need to buy, but I doubt we will, because the owners will argue this squad has got us where we are (which is true). They've never been ones for recognising we need reinforcements and acting on it quickly, it's always been an "it is what it is" stance until we can get to the Summer. When we've bought in January over the last few years has it ever really ever been to consolidate a challenge? It's always been more because an opportunity to buy someone a bit earlier has occurred, for one reason or another.
Slot can rest Gravenberch by playing Endo, he's just chosen not too. The same can be said in other positions too. He's giving the three contract players a wide berth and as much game time as he can, when arguably they are the next few players who need a breather. If we lose the title it won't be because we didn't buy, it'll be because we didn't make the best of the squad that we have at our disposal.