According to the documentary Jurassic Park, a T-Rex can clock in at 35 mph. Plus, in the area of a football field, if you do get any kind of a lead, it can just cut you off when you need to turn.

I was doing some research to see if this is feasible, and found this page with this passage:

(Though 12 miles per hour approaches the top speed of a typical human, depending on conditioning—it equates to a 20-second 100 meter dash or a 5-minute mile—the T. rex’s slow acceleration and inspiring teeth would give the average runner a reasonable chance of outsprinting or outmaneuvering the lumbering predator.)

So yeah I’m gonna spend 3 weeks training to run in the indestructible bunker, then I’m gonna spend every day for a week sprinting around the T-Rex until it can’t follow me anymore. It will still be able to lash out after it collapses, so you can’t just walk up and kill it, but you can harass it any time it tries to take a break to eat or drink for a few days. Eventually it’ll be too weak to lash out, and you can safely walk up and cut a major artery or something.

Or you can stab it with a poop knife while it’s asleep in the first few days, and have it die from an infection over the course of a few weeks