The former AC Milan and Chelsea striker, a hero of Ukrainian football for more than a decade, will quit the national side after his country co-hosts the Euros with Poland in June just three months before he turns 36.
His stature is such that just his presence on the field - even for a short while - could provide an inspirational focus for the team when they face Sweden, France and England in Group D, Ukrainian commentators say.
Injury could be his biggest challenge, though, as he works first on getting back in the Dynamo Kiev team where he started and may end his football career.
"I have had this twice," Shevchenko told Reuters, slapping his problematic right thigh. "But I still have time to prepare myself.
"I have only just recovered and set about working with the squad. I am preparing myself really seriously. It's very important for me to play a few matches to be able to get game practice. These months are crucial."
The European Championships, the biggest ever sports event in Ukraine, looms large.
"Whether I play or not depends on my fitness. If my fitness is at its best and I feel I can help the team, then I'll play," said Shevchenko, who has also had to come to terms with chronic back pain.
"I just have to live with that."
Another stumbling block could be Ukraine coach Oleg Blokhin, parachuted in a year ago to boost their Euro chances and not certain to pick Ukraine's greatest ever goal-scorer.
Asked earlier this month about Shevchenko, Blokhin replied: "Names do not play football ... if they did, I could be playing now."
Media reports have linked the man known to millions as "Sheva" with a possible move to Major League Soccer in the United States to follow in the footsteps of former England captain David Beckham.
"I am not considering any specific proposals at the moment," Shevchenko, whose wife is American, said at Dynamo's Koncha Zaspa training ground.
"There are always offers... but I have to be 100 percent certain that I want something, that my health permits me to do something and that I still have the motivation to go to training and the football pitch."
Shevchenko scored 175 goals for Milan between 1999 and 2006, winning a Champions League, before a difficult spell at Chelsea. He is the all-time top scorer for Ukraine with 46 goals.
