I know what you mean - but, when was the last time that MB played? Without checking, it was probably a month ago. Also, he was coming back from injury then. I'm worried that he could be a bit rusty as he hasn't had any significant game time this season.
Actually, as I was typing, I looked it up:
01/09 Sale Sharks
29/09 Gloucester Rugby
06/10 Saracens
13/10 Agen
TOTAL 320 minutes
I'm not 100% sure this is correct though - as I though he went off with an injured wrist in one of the games.