It’s been a whirlwind few days for Adrian.
But the calf injury Alisson suffered during the 4-1 win has suddenly thrust him into the spotlight "for the next few weeks" according to Jurgen Klopp.
The Brazilian was one of the Reds standout performers last season and filling his boots will be no mean feat for the summer arrival.
But there are two key statistics that should give the fans hope that the Spaniard will be an able deputy.
Klopp described Adrian’s signing as the “perfect solution” when he came in to replace Club Brugge-bound Simon Mignolet.
Citing the “talent and experience” of the 32-year-old, who made more than 150 appearances for West Ham, Klopp said Adrian “has the highest quality”.
The German added: “With Ali and Simon, I felt like we had two ‘No.1s’ and in many ways we have repeated that with Adrian. This is important.
“They are big gloves to fill because Simon was such an outstanding professional and contributed to the group even when not in the starting XI.”
But it’s not just Mignolet’s position in the squad that Adrian now needs to emulate.
Having come on to a warm Anfield reception under the lights on Friday night, the ‘keeper went on to have a solid if not spectacular first outing.
He was at his best to deny Moritz Leitner but was beaten by Teemu Pukki's composed 64th minute finish to end any hopes of a maiden clean sheet.
After the match Trent Alexander-Arnold talked up Adrian’s integration into the squad and insists his new team-mates will help him adapt to their style of play.
“We will be able to make good connections with him and I think a lot of the lads have made bonds with him already because he's such a good lad off the pitch,” said the England international.
“He's a great lad to have around and obviously he is playing now, that is good for him and us.”
Naturally you would expect his new manager and team-mate to talk up the goalkeeper’s qualities, but what can we learn from his time and performances in east London?
Alisson kept 21 Premier League clean sheets and a further six in the club’s victorious Champions League campaign as he claimed the golden gloves in both competitions.
Adrian’s best league return during his five seasons in England is just nine but considering the respective teams both were playing for that’s hardly a fair comparison.
Equally the fact Adrian’s average save percentage is more than 5% lower (71.64% compared to 77.1%) than Alisson’s in the Premier League and that his passing accuracy is down significantly (47.22% to 80.3%) are not really of any significance.
For example, having come on in the 39th minute against the Canaries, his pass completion percentage was at 77.8% and just short of his counterpart’s 81.8% in the same game. This suggests the passing style Klopp demands of his goalkeepers is something the former Real Betis man can adapt to, it’s just not something that he’s every previously been asked to do.
What’s more, there are two statistics that will give Klopp, Adrian and the fans hope that Alisson’s absence won’t be as keenly felt as it would have done this time last season.
Adrian only played more than 30 league games in two of his five seasons at West Ham and thus the 2014/15 and 2015/16 campaigns are the best to compare with what the former Roma stopper has done since arriving in Merseyside.
Despite Alisson’s impressive first campaign in England, he made three errors that led to goals – something Adrian has never done. In those two 30-game plus seasons, he made just two errors that led to goals in each.
Again there are contributing factors. The fact Liverpool play a higher line and leave their goalkeeper more exposed than West Ham will have done for example. But that’s still a very low number that should give all in red confidence.
Also according to the statisticians at Opta Liverpool’s Expected Goals on Target (xGoT) faced in the Premier League last season was 27.53. The formula for coming up with this precise number is broad, but in essence it means that from the chances created against them the runners-up should have conceded 28 goals.
They actually let in a league-low 22, suggesting Alisson saved six more goals than the average goalkeeper would be expected to from those shots.
In Adrian’s 38-game 2014/15 campaign West Ham’s xGoT faced figure was 55.09 but they actually only conceded 45, meaning he saved 10 more goals than expected. The following season, in his 32 matches, those figures dropped to xGoT faced at 41.78 and 37 conceded – again meaning he prevented five goals more than the “average” goalkeeper would.
These numbers saw him ranked second and third in the Premier League in terms of Expected Goals on Target prevented across the two campaigns, with his average score of 7.44 actually above Alisson’s figure of 5.53 for 2018/19.
While statistics can never truly tell the story, there is plenty of evidence to suggest that Adrian could be a more than capable deputy when called upon over the coming weeks.
See how Adrian and Liverpool get on against Chelsea in the UEFA Super Cup live on BT Sport 2 and BT Sport Ultimate from 7pm on Wednesday!