Okay, figured it out. I had to leave the MLBTV app on my phone and go to the app from my Roku and there it was. I'm watching Rice vs Texas Tech.
Okay, for anyone else, this is what you have to do to watch the games. You need a MLBTV subscription. It's free. Just create an account with email and password.
Now here's the tricky part. I have Sling as my internet provider and I have the sports add on that has the MLB network. This apparently will suffice when using Roku or another service that carries the MLB network.
Download the MLBTV app on your roku and sign in using your MLBTV subscription you just created. Scroll down and you will see the Shriners children's classic link. For some reason it's not there on the app on my phone.
I didn't have to pay anything. Now I'm not sure if you're not paying in some way for the MLB network, you're MLBTV subscription will allow you to stream the games. Maybe being just college baseball, the MLBTV subscription is good enough? Not sure but give it a try and if you need to pay for the MLB network, it's $24.95 a month but check your internet provider for add ons. My Sling add on that has multiple sports channels including the MLB network is only $15 a month.