Lamela has been in fine form at Roma this season, scoring 12 goals to help the club's fight for European qualification.
The 21-year-old's performances have led to calls for a place in the Argentina side, but he has insisted that international recognition will only come with focus on playing for Roma.
He told ESPN Radio in South America: "I was close to joining Barcelona, but I don't regret that, as I don't know what would've happened there.
"If I am to play for Argentina, then it's up to me, as I must continue performing well to get an opportunity.
"Fortunately things are going well for me. The key is to train consistently and put yourself on show with a great club side."
Lamela's sole cap for Argentina came in a friendly against Paraguay two years ago.