Ramsdale had suffered relegations with Bournemouth and Sheffield United during his earliest days in the Premier League, but Arsenal were nevertheless convinced by his qualities in between the sticks.
The Gunners paid £30m to sign the England international, who was not welcomed to the club warmly by the entire fanbase, but he quickly won over the naysayers and silenced critics with a string of acrobatic and effective performances.
Last season, Ramsdale kept 14 Premier League clean sheets as Arsenal spent 248 days at the top of the table, and only Golden Glove winner David de Gea - now without a club for nearly a year - recorded more shut-outs in the top flight.
However, Arteta sought a goalkeeper with superior footwork and pursued Brentford man Raya, who joined on loan in the summer window with a £27m permanent option, which is expected to be triggered this summer.
Jens Lehmann 'never understood' Raya decision
The Spaniard has been Arteta's number one ever since the end of the September international break, largely restricting Ramsdale to cup matches and Premier League games against his parent club, which Raya was ineligible for.
Ramsdale's demotion to second choice came only a few months after he signed a new long-term contract at Arsenal, but he is now expected to push for a move away from the Emirates Stadium this summer.
Criticism of Arteta's bold decision has largely subsided, but Jens Lehmann - a former Premier League winner and Champions League runner-up with the Gunners - still believes that Ramsdale should have remained first-choice.
"I never ever understood the (Aaron) Ramsdale decision. If you have a good, brave English keeper at a big English club doing well and then you bring in a Spanish guy who's never played for a big club at that level - it just doesn't make sense," Lehmann told the Daily Mail.
"The keeper is the most important position in the team. If I were Ramsdale, I don't know how I would react because it's not easy at that age. When you're older, it's different."
Does Arteta's Raya decision really make no sense?
There can be no questioning the credentials of a goalkeeper who helped his team go an entire Premier League season unbeaten, but the statistics show that Arteta's decision to promote Raya to number one has been vindicated.
The 28-year-old is already on the brink of winning the Premier League's Golden Glove, having recorded 14 clean sheets in just 29 appearances, and a 15th versus Bournemouth this weekend could be enough to see him collect the individual accolade.
Having a defence comprised of Ben White, William Saliba and Gabriel Magalhaes is a major help, but few can match Raya when it comes to collecting crosses; he ranks in the top 1% of goalkeepers in Europe's big five leagues in that metric.
Of course, every Raya mistake - and there have been a few of them - have reignited the Ramsdale debate, but barring his howler of a pass to Cristian Romero in the North London derby, he has been very easy on the eye on the ball.
In contrast, Arsenal's two wins over Brentford this term came in spite of a couple of Ramsdale clangers - including one which led to a goal for Yoane Wissa - so to many Gooners, the Raya decision makes a lot more sense now than it did several months ago.