Yes, it is true! At least for this week anyway - he is taking his turn as a goalie this week for his team. He was really excited about it actually and had to flip a coin with his friend Karsen to see who would get to try it out this week, since they both wanted to volunteer.
His coach, Jeff, worked with him for a while and he was blocking shots right and left.
They played a game called Dead Rat where all his teammates lined up and took turns shooting on him. If he blocked it they had to go lay down on the ice and put their arms and legs up (like a dead rat) until someone made a goal. Markus had his whole entire team on the ice except for the last two players when Luc made his shot. Otherwise he would have had a shut out. Not too bad for his first time, ha?!