The teenager had to find out through a voicemail from the national side trainer that he would be joining the preliminary Germany squad for the European Championship
The 18-year-old was attending a history lesson and was forced to ignore his phone, but fortunately the coach left a message detailing his selection.
"The nomination came for me, quite unexpectedly. When I listened to my voicemail this morning during the school break, I had a message from Joachim Low," Draxler told Bild.
"This is a great honour for me. Of course I will do my best."
The midfielder will now travel to Sardinia to prepare for the tournament in Poland and Ukraine instead of travelling to the United States of America for pre-season with Schalke.
The selection was met with great enthusiasm by the Gelsenkirchen club, with general manager Horst Heldt and coach Huub Stevens both wishing the teenager well.
"This is a great honour for Schalke and a great thing for Julian," said Heldt, whose thoughts were echoed by Stevens: "Julian can learn a lot in the coming days."
Draxler will need to impress if he is to make the final cut of 23 players on May 29 as Low will need to disappoint four players from his preliminary 27 selections.