Sprinting injury

Also, i got an injury sprinting a few months back, i was sprinting and i felt a pain in my leg and then my leg felt numb. I left it for a week and went sprinting again, but the same thing happened. I left it for 3 weeks, played rugby,did some sprinting in the game, and felt nothing. But that same week i went running up some hill and it pulled. It’s an odd injury, it doesnt occur unless i properly concentrate on sprinting, so if im just running as quick as i can playing football or rugby, it doesnt occur, but if i try sprinting and try run as fast as i can, the injury will occur, this made me think it might have something to do with stride length, as i normally increase my stride length when im just sprinting.
Anyway I left it for 2 months and i havent been sprinting. I played football this week and ran quick, and the injury didnt happen, but my leg felt numb for a while during the game, i dont know if thats the injury, or because i havent played in a while or maybe its psychological? Any advice with this injury?

The main thing about this injury is, you feel it building up. So if i was sprinting, i can feel it about to go, it doesnt just happen out of the blue as to say

Thanks for any help with either of my injuries, it’s greatly appreciated