Storing a bag before a game?

My son's birthday is in August, and he's a baseball nut. We were supposed to go hiking in Glacier National Park this summer, and catch two Mariners games while we went in and out of Seattle. However, my mom's leukemia came back, and now further chemotherapy is useless, so we had to cancel those plans. Kid handled it like a champ, but I know he was disappointed. But he understood.

I still want to do something for him though, and by happenstance I found a roundtrip ticket from where we live to Houston for dirt cheap. The flight gets into IAH twoish hours before the game (vs Tampa Bay) and takes back off at 6am. I was going to just Uber back and forth from the airport to the stadium, sleep in the terminal with him. Roughing it, but that's half the fun!

But I suddenly realized if we bring a backpack for a "personal item", there's nowhere to store it. Immediately I thought of airport lockers, but turns out those haven't existed since 9/11, and Minute Maid's policies preclude backpacks. So I was just curious if anyone has any tips, tricks, or hacks on where we can stash our gear while we watch the game.

Thanks y'all, I appreciate you.