Kuznetsov has really bad season this year in comparison to previous ones. 10 wins/12 losses, and huge drop in the ranks (272th place). He lost against a bunch of very average players, and in the last 6 matches he won only once.
Herbert didn't play much this season with only 10 matches, and winning half of them. It is because unfortunately he suffered a right shoulder injury, which ruled him out for nearly three months. He came back, lost to Hanescu (two tiebreaks), won against Olivo (good clay courter), and lost to Arnaboldi in Roland Garros qualifications – 3 sets, and the last one lost 25-27, not easy to break, isn't he?:)
However, grass is fast surface, and the faster the better for Pierre, because he is one of these players who rely on their serve and it's quite efficient I must admit.
All in all, Pierre coming back to form, on grass which is a surface far more favourable for him, than for Kuznetsov. With his serve, and doubles experience, he should take it.