And rest……
The AZ tie was positioned as Postecoglou’s first big test. That Celtic negotiated the tie and are in the Europa League groups is well ahead of where many of us thought we’d be in June.
So, despite a nerve shredding defeat in the second leg that brought back memories of Be’er Sheva, this was one to be savoured.
Aggregated Data
In many ways it was a classic old school European cup tie where each side dominated their respective home ties. Some key metrics from each and the aggregated view below:
First Leg

Second Leg

Aggregate

Over the two legs, a very close set of data, but Celtic judge edge it with superior xG, shots and big chances whilst forcing 2 more saves from Verhulst.
AZ had a lot of possession in Celtic’s box – mainly the result of many long throws, passes and crosses resulting in poor quality touches.
Stylistic Differences
AZ also “out packed” Celtic which is rare. Meaning they had more forward passes that took opponents out the game. AZ’s “verticality” – how quickly they looked to get the ball forward - is very much their signature style whilst Postecoglou puts greater emphasis on possession retention.
I likened AZ to a more sophisticated Cluj. Although in the second leg, close you eyes and it was Cluj! That is, they identified weaknesses in Celtic’s back line that could be exploited by playing a lot of quick and direct passes.
On Twitter, @jucojames pointed out that whereas Bain could be playing the ball 30-40 yards from his own goal, thus reducing the space between the Celtic defence and himself as the last line, Hart, older, taller, bigger, less mobile on his feet, tends to deal with possession around the edge of his own penalty area. What this means is, with Celtic playing a high defensive line, there tended to be a large space between the goalkeeper and back four.
Secondly, Celtic’s back line is relatively small. Neither Welsh or Starfelt are much above 6ft and Ralston and Taylor are quite diminutive. Ralston is, however, strong with a good leap.
Their first goal came from exploiting that very territory. Welsh was forced to turn against a very fast clearance from Verhulst, and there was a “gap of uncertainty” between he and Hart. A ball that spun and slowed after brushing Welsh left Hart stranded and his momentary lapse in decisiveness allowed Aboukhlal a tap in.
AZ nearly doubled their attempted long ball passing compared to their two previous games this season.

AZ even brought on a centre back (Beukema) to play as centre forward as they doubled down on this strategy. This nearly paid off as he set up Joku for their one big chance of the second half on 79m. That poor finish was another feature of their play, and as the xG numbers show, Celtic got what they deserved.
In the second half, Celtic just about withstood the barrage. The defence’s aerial duel numbers were impressive:

Before anyone jumps on Starfelt, his tackle numbers were W5 L0 in line with his scouting data showing he is very strong as a defender on the ground.
Defensive 3rd Wins are the number of times the player won back possession in their own defensive third.
The Celtic back line therefore dealt well overall with the aerial bombardment.
Although AZ played through Celtic’s lines very successfully (the Packing Score of 383 would be higher than any other opponent since the calibre of AC Milan, Lille and Lazio), they did not get past the defenders to the same extent,
Celtic had 29 instances of defenders being taken out the game with forward passes. This IS high, but not even the highest of the season (Midtjylland away). Last season, that number was matched twice – both 1-4 defeats to Sparta Prague and The Rangers.
Celtic’ back four largely stuck together as a unit, and the most important aspect is that they did not fold after the first half calamities, as has happened in the past.
AZ Fitness
One of the many elements of variance to mitigate in these early season European qualifiers is that not all leagues follow the same calendar. Scandinavian countries can often be largely Summer based. Therefore, you can be playing teams at various stages of their season. And match sharpness can overcome gaps in perceived quality.
In this instance, the Dutch league was only two games in compared to three for Celtic. However, AZ, supported by their FA (what witch craft is this?), elected to take the weekend off to concentrate on the Celtic tie. What that meant was they only had a maximum 180 minutes in their legs by the second tie.
Celtic, by comparison, were playing their 10th match of the season with much the same threadbare squad.
So, surely freshness and preparation beats two matches a week?
Well, maybe in February!
In the first leg, AZ posed problems for Celtic from the start but tended to play in bursts.
Their opening 10m was strong – Pavlidis big chance until Celtic scored
Celtic largely controlled the game until the 40th m
40-45 they had a series of corners and pressure
45-60 Celtic under pressure again until the 2nd goal
Edouard comes on 60th min
From Aboukhlal’s header on 67m over from a corner NO SHOTs until a last minute 40 yarder
AZ seemed to tire badly after 67 mins, but struggled in general when Edouard came on to allow a more focussed attack and hold up play from Celtic.
In the second leg, Celtic were again under pressure up to going 2-1 down (26m). The game then became even up to half time with 3-2 Celtic shots between 26m and 45m.
The pressure AZ exerted after half time was extraordinary. 7 times in 15 mins Celtic gave up possession in their own defensive third such was the intensity of the high press and barrage of high balls. AZ had 5 attempts between the 46th and 55th minutes.
Then on 60m Edouard came on for Rogic, who had not completed a pass in the half, and the home teams efforts subsided for 10 minutes. Celtic had the next 7 attempts at goal between the 59th and 70th minutes.
AZ substitutions breathed new life into their efforts but they never recaptured the intensity of the second half opening burst. The 79th minute big chance for Poku was an outlier and AZ did not fashion a shot after the 81st minute.
I believe AZ got it wrong having the weekend off and the lack of “match legs”, that bit of extra sharpness and intensity was visibly absent in both ties. Celtic were the fitter side.
And that augurs well for the Derby.