Pretty sure Young has played a handful of games at 8. I'd start Odogwu. Think he earned it last week, and his brief cameo against Bristol was none too shabby either.
Think I'd go Wolstenholme over Velacott at the moment too. I'm sure Velacott will get back to his best soon enough, but he's had a very long injury lay off and didn't look like he was quite firing on all cylinders against Bristol.