Here they had a 'keeper that would guarantee them an extra 10-15 points over the course of the season.
Those points, supporters enthused, could be the difference to help them bridge the gap to rivals like Chelsea and Manchester City in their bid for a first title in 12 years.
There was one problem, though, Cech remained the only signing of the summer window as Arsene Wenger put the cheque book back in the drawer.
'Outraged at inactivity'
Gunners fans were outraged at the lack of activity and urged Wenger and the board to bolster the team with some quality marquee signings.
The window slammed shut without any further reinforcements, though, and the club's failure to listen to fans looks like it may cost them dearly.
Arsenal seemed to be one of the main contenders for the title despite starting the season with a 2-0 defeat to West Ham.
Serious doubt over title credentials
But injuries, a lack of strength in depth and defeat to West Bromich Albion at the weekend has cast serious doubt over their title winning credentials in this most wide open of seasons.
Wenger must now do without midfield lynchpin Francis Coquelin - the man who arguably makes their team work - for up to three months after he was injured in that defeat to West Brom.
It leaves the Gunners looking short and Wenger has admitted he may now be forced to begrudgingly dip into the transfer market to rescue their season.
The Gunners currently have eight first-team stars on the sidelines with Coquelin although there is some solace in the news that Aaron Ramsey has returned to training.
They face an uphill task to make it through to the knockout stages of the Champions League, needing a win against Dinamo Zagreb tonight to stand any chance.
Club should have listened to fans
So for the sake of listening to their supporters Arsenal could well have squandered a big chance this season.
A very good chance to win the league, a chance to progress in Europe and given the level of threat from teams such as Liverpool, Everton and fierce rivals Tottenham Hotspur could even do the unthinkable and miss out on the chance of Champions League football which has for so long seemed a divine right.
Wenger is a notorious critic of the January window but even he has now been forced to admit: "I will do what is needed in January, knowing that it is not an ideal market."
Not doing what was needed in the summer, though, could yet be one of the biggest regrets of his tenure to date.