National 10,000 meters champion Robert Kajuga will be out of action for up to six months with an Achilles heel injury he sustained in the IAAF World Athletics Championships in Moscow, Russia.This was confirmed on Monday by the Rwanda Athletics Federation Secretary General, Johnson Rukundo. The team was due to return home on Monday evening."It is a very bad injury, which is really sad news for us all because he could be out for up to six months, but we will determine the exact extent of the injury once the tam is back,” Rukundo told Times Sport.The 27-year old started well in the men’s 10,000 meters final on Saturday, keeping pace with the frontrunners until about four laps to go when he stumbled to the ground.In the men’s marathon, Jean Pierre Mvuyekure also failed to finish the race.Rukundo said this is a real concern for Rwandan athletics."We need to sit with them and see what and where things went wrong, especially for Mvuyekure; otherwise you can’t just judge them.  Nonetheless, there is a cause for concern as to what led to him to pull out with just seven kilometers remaining.”Rukundo said they are planning to use more young athletics for the next championships.Uganda’s Stephen Kiprotich won the world title, adding to his Olympic gold medal he won at the 2012 London Games.