Wenger had an impact
It's been suggested recently that Arsenal's players are no longer responding to Arsene Wenger. Given the way they slid to a 3-0 loss at Crystal Palace, in particular, it wasn't an unreasonable assessment. But on this occasion, the players did respond to their manager.
The Gunners struggled badly for possession in the first half against Manchester City - they had just 30 per cent of the ball, a statistic that's almost unheard of for Wenger's Arsenal. They couldn't get forward and it looked like a matter of time until City scored and sailed serenely into the FA Cup final.
As it happened, City did score 17 minutes into the second half - but despite that, by then the balance of the game had already changed. Whatever Wenger said at half time, it made a real difference. There weren't any major changes of personnel at the interval, but the Gunners were hugely improved from the start of the second period, pushing forward and creating chances.
They weren't totally dominant, hence Aguero's goal and Manchester City's 58 per cent possession in the second half, but they were in the game - more than could be said for most of the first period. Once they were in the game, if they took their chances and City didn't take theirs, the Gunners were on the way to a final against Chelsea. That's what happened, thanks to an equaliser from Nacho Monreal and an extra-time winner from Alexis Sanchez.
Time to announce that contract?
It's been widely rumoured for some weeks now that Arsene Wenger may have agreed a new contract to remain as Arsenal boss, with just one delicate issue: when could the club announce it?
Fans have understandably been dissatisfied with a poor season in which they may miss out on the top four altogether, so the FA Cup was their last hope of success - and their last chance to create the sort of brief feelgood factor required to tell the world that Wenger is staying, without complete uproar from a large section of their support.
Straight after an FA Cup semi final victory might be just about the best possible time. Wenger was saying nothing about his future immediately after the game - asked in the post-match press conference whether this result could help him and the team going into next season, a wry smile crossed his face as he responded simply: "I don't understand the question."
But will there now be an announcement soon confirming that Wenger is to remain in charge?
City missed injured Silva
Manchester City's domination of possession early on was aided by greatly by the presence of David Silva, the man who looked most likely to fashion a goal. The Spaniard was cleverly finding pockets of space with regularity between Arsenal's midfield and defence, until a challenge from Gabriel ended his day after only 23 minutes.
Pep Guardiola looked incensed by the tackle and several City players made a point of going over to the referee Craig Pawson to complain when Silva had to limp off. Replacement Raheem Sterling didn't have the same impact, and was subbed himself in extra time. Defeat means Guardiola's first season at City will end without a trophy. "We will be better next season," he vowed afterwards.
Three at back working for Arsenal
The Gunners have become the latest side to adopt the latest trend of a three-man defence, making the switch for their match at Middlesbrough last week. It worked: after succumbing at Palace days earlier, this time Arsenal won 2-1.
Wenger admitted that the switch had been made with the FA Cup semi final in mind - and that it was also about giving the players something new to think about, at a time when they needed their minds taken off a sequence of bad results.
The formation paid dividends again against Manchester City, as the Gunners emerged triumphant. Wing-backs Alex Oxlade-Chamberlain and Nacho Monreal couldn't get forward as much as Arsene Wenger would probably have hoped in the first half, but they combined for Arsenal's equaliser, with Oxlade-Chamberlain providing the deep cross for Monreal to fire home. Gabriel and Rob Holding also had decent games either side of Laurent Koscielny in the centre of defence.
The effectiveness of Arsenal's 3-4-2-1 system persuaded Pep Guardiola to switch to three at the back early in extra time, as he made the rather unlikely decision to bring on Fabian Delph for the injured Sergio Aguero, as Fernando came on as a third centre-back in place of Fernandinho, who had also picked up a knock. It didn't work as well for City - within two minutes Sanchez had netted the winner.