Performance matters more, and he only got that in the second half against Shakhtar Donetsk, when Manchester City could have scored five goals but ended up with just two. It's the first half that creeped him out. Because something rather unusual happened in the first 45 minutes of Manchester City's match against Shakthar Donetsk on Tuesday night: His team had less of the ball than the opposition.

How unusual? In 56 Champions League and Premier League matches since he arrived at the Etihad, it's happened only twice over 90 minutes. Both times were last season, both against Barcelona.

Possession is not inherently good or bad. Better teams usually have more of it, simply because worse teams often tend to defend more. But there are plenty fine sides who are just as happy without the ball as with it.

Manchester City are not one of them, however. And while numbers can only tell you so much, when a team that is used to having the ball roughly two-thirds of the time (69 percent possession in the Premier League this year, 64 percent last season) drops down to less than 50 percent -- especially at home, especially against Shakhtar Donetsk -- it's time for closer scrutiny, particularly when it coincides with your opposition carving out as many good chances as you did in that first half.

So you just know that Guardiola is bringing out the giant microscope. This is a guy who tinkered ceaselessly mostly with formations and tactics (but occasionally with personnel) both at Barcelona and at Bayern. (Before you take that as a knock, it isn't. The search for innovation and improvement on something that already works pretty darn well is a sign of intelligence, no matter what portions of the British punditocracy, the guys who derided Claudio Ranieri as the "Tinkerman," think.)

What might he have concluded form the first half? City were pretty much at full-strength, apart from the absence of Benjamin Mendy. What's more, they didn't play particularly badly. Watch the tape again and you'll note few instances of individual blunders. The issues had more to do with the way Shakhtar set up than anything City did wrong, and for that, credit has to go to their manager, Paulo Fonseca. He's an interesting case study.

Born in Mozambique, Fonseca was a run-of-the-mill central defender who turned to management and seemed down and out after a disastrous campaign at Porto in 2013-14 that saw him finish third. You have to go back to 1976 to find the last time the club finished lower. But after winning the Portuguese Cup with Braga the following year, he landed the Shakhtar Donetsk gig, replaced the legendary Mircea Lucescu and won a league and cup Double. Evidence that clever people learn from their mistakes.

Against City, his players did two things exceptionally well. He lined them up in a 4-2-3-1 but got his wingers to tuck in when not in possession, essentially creating a dense central area that forced City wide and disrupted their possession. Guardiola's crew could go wide, but once they did, they couldn't work their back across and pull players out of position. Or, as Pep put it: "In the first half, we had problems. We couldn't make enough passes in a row."

That part is not rocket science. Other teams have done it against City to varying degrees of efficacy. But Shakhtar did it very well (Guardiola described them as "outstanding" afterwards), and that warrants a brief digression.

One thing we often forget is that in the Champions League, even the so-called minnows are giants in their domestic leagues. In other words, most of the time they're used to being the team with the ball, breaking down opponents who park their bus. Being able to make that transition in Europe when they come across a Man City, a Barcelona or a PSG is no mean feat.

The other thing Shakhtar did very well -- and which likely caught Guardiola by surprise -- is take care of the ball when they won it back. City defend by pressing (it's no secret), and pressing is most effective against teams that try to break quickly and "vertically." That's because, simply put, it's more difficult to move the ball directly and at pace, which makes it easier to press and win it back. Yet most teams break quickly against City because their press leaves gaping holes and one-one-one situations at the back. Counterattacking in this way is high-reward with relatively low-risk: at best you have a striker in space against John Stones or Nicolas Otamendi, at worst you simply give the ball back to City straight away, but your defence is set, and the process starts again.

Shakhtar chose a different approach. When they won the ball back, they kept it. Even if meant moving sideways rather than forward at first, they were happy to do that and happy to invite City to press.

"We're not used to teams who come here and keep the ball the way they did," Fabian Delph said afterwards. "It was really difficult to get the ball off them in the first half."

Part of it is down to the fact that the likes of Ismaily, Fred, Marlos and Taison are technically gifted players who are very comfortable on the ball. But part of it is that it's a whole heck of a lot easier to play "keep-away" when you can go in any direction and aren't entirely preoccupied with going forward. In this sense, Fonseca's team were extraordinarily patient. They allowed City to chase them around, knowing that pressing inevitably causes you to lose your shape, and then picked their spots with accuracy once it came time to move forward. That's how they created as much as they did in a very even first half.

It unraveled after the break partly because Shakhtar declined physically and largely because of Kevin De Bruyne's long-range ballistic effort. It wasn't very Guardiola-like (just two of City's 19 league goals this season have come from outside the box) but at that stage, working the ball closer to the opposing goal was proving to be very difficult. And sure, in football, often individual quality makes all the difference. From there, Shakhtar had to open up and City went to town.

The question is whether other teams, perhaps those with better players, can emulate Fonseca's blueprint of stout, well-drilled defensive density coupled with patience and quality in possession. Not many have that combination but even if some do, you can be sure that Guardiola will be working on an antidote.