If Mikel Arteta needed any further proof that the vibrancy of youth, rather than the lethargy of experienced players at Arsenal, is key to their chances of success this season, then performances from two players on Saturday provided a crucial warning.
Willian's dire start to life at the club was once again on display as the 32-year-old was ineffective and wasteful, not for the first time in his Gunners career, lacking any sort of energy or drive to deliver quality to Pierre-Emerick Aubameyang as Newcastle held firm in the FA Cup third round tie.
Then just before the hour mark, Emile Smith Rowe was introduced and his performance demonstrated everything the Brazilian's lacked, not only with the decisive opening goal in Arsenal's 2-0 victory against Steve Bruce's men after extra time but also the 20-year-old's resilience.
Emile Smith Rowe's latest performance in his rise at Arsenal saw him score against NewcastleInsurance Loans Mortgage Attorney Credit Lawyer
The midfielder was shown a red card in the third round FA Cup tie against Steve Bruce's men
Disaster appeared to have struck when Smith Rowe was shown a red card by Chris Kavanagh for a challenge on Newcastle midfielder Sean Longstaff in the dying seconds of normal time, only for the referee to downgrade the decision to a caution after consulting the VAR pitch monitor.
But having been correctly offered the reprieve, he became the central figure in the game and elevated an insipid Arsenal into a side that came to life with his vibrancy, particularly once he had brilliantly collected Alexandre Lacazette's flick-on and finished into the far corner off the inside of the post.
'He's becoming more and more important to the team and he showed it again when he came on,' said Arteta of Smith Rowe after seeing his side record their fourth straight win across all competitions.
'The personality that he plays with, we ask him to be more in the box and today he scored a really important goal for us.
But he was offered a reprieve when the referee downgraded his decision to a caution
Smith Rowe netted and inspired Mikel Arteta's men into the fourth round of the competitionInsurance Loans Mortgage Attorney Credit Lawyer
'It was very impressive because is playing with a lot of personality, a lot of risk. He is playing in areas where he needs to make things happen and he has got the talent to do it.'
Those characteristics not only belong to a man whose electric performance was just the latest in his rise to first-team regular, but to one of world football's most prominent stars who plies his trade at Manchester City.
Smith Rowe is often referred to as the 'Croydon De Bruyne' at Arsenal, with fellow youngster Bukayo Saka the latest player to reference it by posting 'Thank you Kev' on Instagram after their win against West Brom.
'Some people have compared my playing style to Kevin De Bruyne's and that's a very nice compliment because he's a great player and someone I really look up to,' Smith Rowe said previously.
'I'm trying to learn as much as I can from watching De Bruyne and working hard in training with all of the world-class players around me.'
Smith Rowe is called the 'Croydon De Bruyne' in reference to Manchester City's Kevin (right)
Bukayo Saka was the latest player to reference this on Instagram after they beat West Brom
However, the lack of attacking verve among the established members of the midfield - especially given the absence of Thomas Partey through injury - has seen Smith Rowe become, on Saturday's evidence, an indispensable figure in the starting XI, for the time being at least.
The Gunners were struggling to fathom chances and were languishing in 15th in the Premier League table before the midfielder earned his first top-flight start of the season in the 3-0 win against Chelsea last month.
He claimed an assist on Boxing Day thanks to Saka's wonderful - or fortunate goal, depending on whether you think he meant it - but it was his regular occupation of the space in between the Blues' midfield and defence which was of greatest benefit to the Gunners, allowing the full-backs more space out wide with the visitors concerned by his presence in the middle.
Those are the qualities that Arsenal have lacked in recent months but that Arteta praised ahead of the Europa League match against Dundalk last month, stating: 'Emile is a player with an incredible talent.
Smith Rowe earned his first top-flight start against Chelsea and recorded an assist for Saka
'He's a player with very specific qualities to play in those pockets in that position as an attacking midfielder.
'I really like him and