A pulled hamstring is doubtfully going to end up being a real serious injury. If you didn't tear it the first time, your body isn't likely to allow you to use it enough to tear it after an injury. It might take you out of training for 3 to 6 weeks, but if this is a tournament you have really been preparing for and your are a big tournament fighter and really want to do well at, it might be worth it (this is an exercise science degree with a real competitive edge talking- so take it for what it's worth

). Assuming of course the fighter is an adult, if it is a kid it is up the parents, but I would let my fighter go for it.
In that one minute I would use tiger balm and then ace bandage it or tape it. I would also tell my fighter to USE that leg to kick. Most people find that kicking actually pulls the hamstring on the base leg a lot more than the kicking leg (at least on roundhouse, side kick, even axe and spin hook).
So what happened Wade?