The 3rd part of 'Descendants of the Sun' special aired on the 22nd, and talked about producing the drama.
A part of the episode talked about Song Joong Ki's dedication to the role. He had been filming for episode 14, and Song Joong Ki explained, "I felt sorry to the director [that I got injured a little before filming ended]. The director knows my personality. I tried to be even more perfect during action scenes. I know where I'm lacking so I tried to work harder, and the director thought that was dangerous. But when the camera starts shooting, I start working harder, so I thought to myself that I'd be careful. But I ended up getting hurt."
He returned to filming only 2 weeks after he got injured. The director said, "He himself was disappointed [with his injury]. But his acting was amazing. He couldn't even walk property, but he pulled the action scene off."