There seems to be a worrying pattern developing with Murray with regards to mental collapses and match tactics. He got bageled at the World Tour Finals last year against Fed, then again at the AO and now here in Miami, again versus Djoko. Once is one of those things, twice is a concern... three is alarm bells time!
He is clearly lacking the mental strength and more importantly, clarity of mind to maintain his level and stay in the fight and this is down to lack of belief in his game, his strategy and his recent record. Again, I would argue he actually threw that match away rather than got beat - even though the third set suggests otherwise.
Murray should have won the first set. End of. His first two returning games were very impressive. He stepped in, took the ball early and hit aggressively. You could clearly see Novak was rattled right from the start. Murray got the deserved break and was off to a good start and should have kept that level up. Instead of consolidating the break, Murray made poor shot choices and hit straight back to Nolé when a clear court was sat in front of him for easy winners. Why? Because he's over thinking, putting too much pressure on himself by trying to win from the back of the court in long exchanges and knows full well, the ball will come back.
My biggest frustration with Murray (apart from his poor serving) is his lack of net approaches. When he did attack the net (rarely), it clearly put pressure on Novak's shots and you could see he would get some in-roads into Nolé's game. Yet instead, Murray when having pushed Novak wide, would instead be happy to sit back, wait for the deep ball to drop, move backwards (!) and then be straight on the back foot again. This only leads to long, lung busting rallies when a great put away volley would cut off the point and more importantly, send a message across the net saying he's in control. Instead, it's the usual "sit back and hit" Murray and there's only one winner doing that. It was infuriating.
For me, there were least one of two times per game when Murray has put a very good double handed shot out wide to Novak's backhand side that is crying out to be followed in. Ok… so Novak might make a winner, some he won't but it puts that element of doubt (and pressure) into his mind. Will Murray come in, won't he?
Right now, Murray's game is all to predictable. Hit left, hit right… repeat. It's like a practice court drill.
If Mauresmo, after nearly a whole year, can't see the issue right in front of her, I wonder what's she's doing there in the stands as she seems to offer nothing to Murray's game since Lendl departed.