Tell them you don't feel like you've been performing up to you standards lately, and so thought maybe you should sit this one out.
Well, there are a few lists on the net. Here's one though I can't vouch for effectiveness... http://madtbone.tripod.com/work.htm I assume you didn't try to tell them back when the schedule was made that you'd need that night off for the game. So, maybe you could try "I know it's embarrassingly late notice, but being a big Houston sports fan, I'd really like to stay home and watch the Texans first Monday Night Football game. I know it's an inconvenience, but I would be more than willing to work it out and make up the time however you see fit, if you could find it in yourself to indulge me this one privilege. If this isn't acceptable, can you instead provide a television here so we can at least keep tuned in to how they're doing? Again, sorry for the late notice, but it does mean a lot to me and I'd be appreciative. I thought this route would be better than making up some lame excuse and being deceptive." You never know.
