The big centre-back has missed almost three months of action with an ankle injury that required reconstructive surgery.
The procedure ruled him out of the remainder of the domestic campaign and put his appearance in Poland and Ukraine in jeopardy.
However, the 27-year-old has been called up by Germany head coach Joachim Loew, raising the prospect of him adding to his 79 international caps.
"He will be challenged by us in training," Loew said. "We start preparations on Friday with only some of our players but we just have to try our best to get the most out of it."
Schalke's teenage midfielder Julian Draxler won a surprise call-up by Loew, who will use upcoming friendlies away to Switzerland and at home to Israel to finalise his squad choice.
The uncapped 19-year-old made his Bundesliga debut just over a year ago and has been in sparkling form this season, helping Schalke clinch a third-place finish.
Loew said the final squad would be announced later this month, adding there would be some changes.
Germany's players begin their preparations on Friday without several key men.
Bayern's players will not join up with the Euro 2012 squad until after the Champions League final against Chelsea, to be held on May 19.
Germany have been drawn in Group B in Ukraine and Poland along with Netherlands, Portugal and Denmark.
Defenders: Jerome Boateng (Bayern Munich), Holger Badstuber (Bayern Munich), Benedikt Hoewedes (Schalke), Philipp Lahm (Bayern Munich), Mats Hummels (Borussia Dortmund), Marcel Schmelzer (Borussia Dortmund), Per Mertesacker (Arsenal)
Midfielders: Bastian Schweinsteiger (Bayern Munich), Mesut Ozil (Real Madrid), Sami Khedira (Real Madrid), Thomas Mueller (Bayern Munich), Lukas Podolski (Cologne), Toni Kroos (Bayern Munich), Mario Goetze (Borussia Dortmund), Ilkay Gundogan (Borussia Dortmund), Andre Schuerrle (Bayer Leverkusen), Sven Bender (Borussia Dortmund), Lars Bender (Bayer Leverkusen), Julian Draxler (Schalke 04), Marco Reus (Borussia Moenchengladbach)