Our man was introduced shortly after Lionel Scaloni's much-fancied side had fallen behind and although he helped to create a number of chances, an equaliser never materialised.
A 10th minute Lionel Messi penalty had put Argentina ahead before La Albiceleste missed a host of chances that could have put them out of sight before half-time.
World Cup 2022 | City players' fixtures
Saudi Arabia attacked immediately from the restart and were rewarded with strikes in the 49th and 53rd minute through Saleh Al-Shehri and Salem Al-Dawsari.
Argentina attacked in numbers for the remainder of the match but couldn't find a way past goalkeeper Mohammad Al Owais.
Alvarez himself had one clear cut chance of his own in the 91st minute when he saw a goalbound effort headed off the line by covering defender Abdulelah Al Amri.
Argentina's clash with Mexico on Saturday evening now becomes even more important before they complete their group stage against Poland next Wednesday.
This result is in contrast to a positive Monday for City's players. John Stones started for England before Phil Foden and Jack Grealish came off the bench in a 6-2 win a few hours ahead of Nathan Ake's 90 minutes in Netherlands' 2-0 victory over Senegal.
We'll have reports of every single City player's involvement at this tournament here on mancity.com and our official app.