The 28-year-old has hit a rich vein of form recently, bagging six goals in six games, including two in his side's 4-1 win against Hertha Berlin on Saturday.
And speaking to Bild after the game, Helmes was coy on his chances of making it to the tournament in Poland and Ukraine.
"I am focusing only on the situation at Wolfsburg. Football changes very fast. Five or six weeks ago, nobody was interested in how I felt," he said.
"[Germany team manager] Oliver Bierhoff and I have talked from time to time. He has called and asked about me."
Joachim Low's men will be in Group B alongside Denmark, Netherlands and Portugal and are considered among the favourites to win the tournament.
Wolfsburg, meanwhile, currently sit in ninth in the Bundesliga, just one point behind Hannover in fifth spot.