Fitness level for game

So after a 2 week heel injury which im still recovering from, today i was finally able to get back on my feet and start running again. It sucks that heel injuries take time to heal back to 100% because were constantly walking but now that the pain has mostly gone away today i was able to start running again and it felt great i decided to run on the tredmill today just so i didnt have to worry about hurting my heel again on a rock or whatever. I ran a 5 mile program which i honestly didnt think i would last because after 2 weeks of no running i thought i was over shooting it a lil bit but here are my results


i know its not where i should be but after a couple more sessions i know i will be back in form
so my question for the readers are , do you have any tips to strengthen stamina and endurance??