The 26-year-old has endured a six-week lay-off after sustaining a muscle tear in Schalke's 3-1 UEFA Champions League defeat to Real Madrid in March, a result that confirmed the Gelsenkirchen's side exit from the competition.
Howedes had previously been absent with a thigh injury, to leave Germany head coach Joachim Low potentially without the midfielder at the FIFA World Cup, which starts in Brazil on June 12.
However, Howedes is set to provide a timely boost for Low and for Schalke, as Jens Keller's men attempt to secure a Champions League berth in the final two games of the season.
"Howedes back in full training, (Christian) Clemens running again. Only (Kevin-Prince) Boateng was rested yesterday," Schalke posted on their official Twitter account.
Howedes made his Germany debut against Uruguay in May 2011, and has gone on to earn 18 caps, scoring once.
Injuries have limited him to 18 Bundesliga appearances for Schalke this term.
