Sampaoli's first match in charge since leaving Sevilla to answer his country's call gave cause for optimism.
Sampaoli's first match in charge since leaving Sevilla to answer his country's call gave cause for optimism as Argentina saw off an under-strength Brazil 1-0 in Melbourne on Friday.
However, there is a long way to go for Samapoli to turn an underperforming unit into the World Cup contenders they should be based on the talent at their disposal.
"It is a huge confidence boost to beat Brazil because for us it is a derby and, going forward, it will help," said Sampaoli.
The 57-year-old has already proven himself as an international boss to Argentina's cost as he led Chile to the Copa America for the first time in 2015 -- beating the country of his birth in the final on penalties.
However, he now has four games to ensure Argentina and five-time World Player of the Year Messi don't suffer the embarrassment of missing out on football's biggest stage in Russia next year.
With only the top four in South American qualifying automatically booking their place in Russia, Argentina sit fifth, which would only be good enough for a playoff place against the winners of the Oceania confederation.
A 2-0 defeat to Bolivia in March proved the final straw for the Argentina Football Association's (AFA) patience with coach Edgardo Bauza as he was sacked.
Indeed, Samapoli will be the third coach to take charge of La Albiceleste in qualifying as former Barcelona boss Gerardo Martino quit following the 2016 Copa America, citing "serious problems" with AFA.
Bauza won just three of eight qualifiers in charge, but his case wasn't helped by Messi's absence for a number of key games through injury and suspension.
Tellingly, Argentina have won five of the six qualifiers Messi has been available for, but just one of the eight the Barcelona star has missed.
Luckily for Sampaoli, Messi's initial four-game ban for swearing at an assistant referee during a 1-0 win over Chile in March was quashed last month, freeing him up to play in the remaining qualifiers against Uruguay, Venezuela, Peru and Ecuador.
"He is the best in the world by a long way," said Sampaoli.
Yet, for all his success with Barcelona, including four Champions League titles, Messi, who turns 30 later this month, is yet to win a major international tournament with Argentina having fallen short at the final hurdle in the 2014 World Cup and 2015 and 2016 Copa America.
Sampaoli has already started to rebuild the team around his captain with experienced figures like Sergio Aguero and Ezequiel Lavezzi left out of his first squad.
That didn't go far enough, though, for many fans in Argentina who want to see a complete overhaul.
Sampaoli certainly won't lack for attacking talent as he tries, in his own words, to "build a team that respects the history of Argentine football".
Mauro Icardi's excellent form with Inter Milan over recent seasons was finally rewarded with a call-up, whilst Juventus's Paulo Dybala, whose style has drawn comparisons with Messi, also started against Brazil.
"We are starting a new era, we need to improve and consolidate an idea and that takes time," added Sampaoli, as he pleaded for patience.
However, time is of the essence if Messi is to have any chance of crowning a glorious career by leading his country to the biggest prize of all.