800m @ 1:58.79 not 100%

Today I ran a race and had suffered a right hamstring strain after the first 200m but kept going. I couldn't go into my fast gear and ran a slow time. I know I am capable of a 1:54 or 1:53 if I am fresh. I also was not fully recovered from the Mile race 2 days ago. I need to be well rested for my next race in order to perform at my maximum potential.