I need some help understanding what "そ," means in the following context, in which two fighters are being forced to fight and are conversing during the fight:
“If you don’t want to die, then fight seriously.”
POV character:「そ、 そんなこと言っても……」
I managed to translate most of the Point Of View character's response; but I don't know what そ could mean in the above sentence. Any ideas?