Has it happened already yet? The only thing that comes to mind which may or may not mean something to you is what my trainer reminds me of sometimes especially when I am or just have competed or sparred against someone bigger.

I find it helps if I can do it and it's simple enough.

Back yourself.

That's it. Trust in the skills you have, the balance etc and you'll probably find with your strong boxing background that you have more you can call on to hold your own than you realise.

Letting your awe of him diminish what you're confident in would be a mistake. Maybe that's not something you are prone to but I sometimes assume things that would work won't without trying them against certain people.