Hello,
There are 2 muscles in the calf a large one and a small one. Both have attachment sites at the knee and the heal via the achilles tendon. Either of these muscles can become strained(torn). As always with a strain the R.I.C.E method is essential; Rest, Ice, Compression and elevation. Use a compression bandage on the calf in the inflamed area, you could also add a heal pad in your shoe to elevate during the day to help. If all this fails see your trainer for a connect to a physiotherapist. Best of luck to you in your fights, you should be fine as long as you take a rest period.