DOHA, QATAR, DECEMBER 04

This season has been quite an education for Julián Álvarez.

From being the understudy to Erling Haaland in his first year at Manchester City to being the sidekick to Lionel Messi for Argentina at the World Cup, Álvarez is learning from the biggest stars in soccer.

He's on the path to becoming one himself.

Two starts, two goals. How about that for your first World Cup?

As someone who once scored six goals in a single match in the Copa Libertadores, the 22-year-old Álvarez seems born to deliver on the big stage.

At the World Cup, he's living out his dream: playing alongside Messi - one of game's all-time greats - in front of fans who are making more noise than any other travelling contingent in Qatar.

'A huge joy,' Álvarez said after Argentina's 2-1 win over Australia in the round of 16 on Saturday.

'I always try to give my best to help from wherever I play. On the field or being on the bench cheering on my teammates. We are going to go down this path to continue making Argentines happy.'

Álvarez has profited from fellow striker Lautaro Martínez's failure to establish himself as the starting center forward for Argentina. The difference in the two players' form was all too apparent against Australia.

While Martinez fluffed two big chances late in the game after coming on as a substitute, Álvarez - the man he replaced - scored with his only real opportunity. The goal summed up the type of player he is, and why he is already so treasured by Argentina's passionate fans.

Allied to his lethal finishing is a relentless work ethic that was demonstrated when Álvarez closed down Mathew Ryan as the Australia goalkeeper dallied on the ball inside his area. Also under pressure from Argentina's Rodrigo De Paul, Ryan took a second touch that was far too heavy and Álvarez nipped in to take the ball off him and shoot on the turn into an unguarded net.

The goal couldn't have been more different to his first at the World Cup, a curling shot into the far top corner at the end of a sweeping 25-pass move.

Tap-ins, curlers, link-up play, intense pressing. It's no wonder City manager Pep Guardiola rates Álvarez highly enough to make him the second striker in his squad to Haaland, to such an extent that Guardiola was happy to offload Gabriel Jesus and Raheem Sterling during the last offseason.

Álvarez and Jesus are similar in the sense that they never give defenders a second's rest. What's different about them is their ability to score goals, with Álvarez appearing a much more natural finisher.

As for Martinez, he seems to have completely lost his composure in front of goal. One wasteful finish over the crossbar in stoppage time, after being teed up by Messi, kept Australia alive in an absorbing match at Ahmad Bin Ali Stadium that had a dramatic ending when Argentina goalkeeper Emi Martinez produced a smothering save with virtually the last kick of the game.

If that had gone in, Lautaro Martinez might have been vilified. He was the subject of much chatter among Argentina fans on social media and the metros back to Doha after the match, none of it flattering.

Argentina coach Lionel Scaloni was not adding his voice to the critics.

'Lautaro has helped us many times so I wouldn't like to go into detail about that,' Scaloni said. 'That would be unfair to Lautaro. He will keep on helping us and making us happy.'

Indeed, Martinez has been Scaloni's go-to striker since the coach took charge after the 2018 World Cup initially on a temporary basis. Martinez has scored 21 goals in that time, more than anybody else apart from Messi.

Now, he is firmly behind Álvarez in the pecking order.

Álvarez arrived at the World Cup on a high after making a string of starts for City, for the first time since joining from River Plate in July, because of an injury to Haaland.

Now he's leading the line for Argentina in its bid for a third World Cup title, and to seal Messi's legacy in front of fans who are pushing the team all the way.

'We will always give our best and support him (Messi) to continue on this path,' Álvarez said.

'We feel at home here,' he added. 'In all the stadiums we have played, most of the people were from Argentina. You feel their breath and how they sing the whole 90 minutes.'