Head to heads are 3-3. Their most recent meeting was in August 2013 in Cincinnati. Querrey took the first set in a tie break but Tipsarevic came back to win in 3.
Tipsarevic is finding his way back after playing very little tennis for a couple of years. He won a Challenger title on clay earlier this month though it wasn’t a strong field.
Querrey had an amazing run at Wimbledon where he beat Djokovic and backed it up with a quarter final in Washington but since then he has been poor.
I favour Querrey to win this but I don’t think he wins in straight sets. Back him if he loses set 1. This could be an interesting one.