Suga can't be at BTS' Gayo Daejeon Special Stage because he was ill at that time so he had to watch it live at the hospital. He saw that Jimin fell down while doing handspring at the start of the performance so he changed because he was surprised. Right after the performance finished, he quickly called Jimin. 

Jimin: I was touched by Suga since he called me after the performance. I kept on dancing on stage, not knowing I was hurt