Argentina currently sit atop the CONMEBOL qualifying section with 14 points from seven games, one point more than Colombia and Ecuador, and two above local rivals Uruguay and Chile.
It is a tight battle at the top and Messi knows Argentina will not be in for an easy ride in the latest edition of the Rio de la Plata derby against reigning Copa America champions Uruguay, but the Barcelona ace feels his side are improving all the time.
"The qualifiers are hard, all the opponents are complicated," he said, before adding: "We are growing. Yes, there is still a lot left to do. But we are getting stronger as a team and as a group."
Messi has not always enjoyed the best of times with his country - in stark contrast to his success with Barcelona where he has established himself as arguably the best player on the planet - but the 25-year-old has been in stunning form for the Albiceleste in recent times.
In his last seven appearances in national team colours, Messi has scored 10 goals, including two hat-tricks.
He said: "I've experienced some sad times with the national team in the past, but now things are better and I hope to continue this way."
Regarding being made Argentina skipper, he added: "Wearing the captain's armband has not changed me. I still do the same things with my team-mates."
Messi could line up as part of Argentina's 'Fantastic Four' forward line on Friday night, alongside Real Madrid duo Gonzalo Higuain and Angel Di Maria, and Manchester City's Sergio Aguero.
Uruguay are not short of firepower either, though, with Napoli's Edinson Cavani, Luis Suarez of Liverpool and Internacional's Diego Forlan all available to coach Oscar Tabarez in what could be an exciting showdown between the two nations in Mendoza.
The last meeting between the teams did not produce many goals but it was not short on incident, with Uruguay beating Argentina 5-4 on penalties following a 1-1 draw in last summer's Copa America quarter-finals.
That was only Uruguay's second win in 14 meetings with Argentina, but coach Tabarez does not believe it will have any influence on Friday's encounter.
He said: "You can't compare this match with that one.
"Argentina have improved a lot with Alejandro Sabella on the bench and are now a very dangerous team. This will surely be the hardest match we will have in qualifiers because we are facing a huge team, and Messi as well."
Following Friday's derby, which will be played for the first time at Malvinas stadium in the western Argentinian city of Mendoza, Argentina cross the Andes to face Chile on Tuesday while Uruguay go to La Paz to face Bolivia.