The Argentine international is set to feature for Marcelo Bielsa's men in their friendly against Holland on Wednesday, but admitted the extended travel involved in representing his country has a detrimental effect on his performances.
"I am no longer 22-years-old, which is the age when you want to take everything on, and making a thousand journeys doesn't bother you," said the 27-year-old.
"We are no longer playing in the street, when you can play 20 games a day and do the same the next day.
"I've got to look after myself now."
The former Lazio star also revealed that he is unfazed by criticism from fans of his displays in the Argentina shirt, especially following the country's premature departure from last summer's World Cup finals.
"For my country I have received more stick than kind words, but I'm still there, and not just by a whim of my own or the manager.
"He (Bielsa) considers me an important player and calls on me for that reason, and I believe I'm still an important player who can bring something to the team."
Veron looks set to occupy a new, deeper role for Argentina, similar to the one he plays at Old Trafford, with Pablo Aimar thrust further forward to become the team's creative influence.
"If Marcelo asks me, I will do it without doubt," said the midfielder.
"I was never a typical playmaker, like Aimar or Riquelme, who always get to goal.
"I was different, but Marcelo thought I could do it and so it proved, but now I will drop back if he asks me to."
