Neither team is hitting, but this is a low price to get Sonny Gray against Adrian Houser.
Gray has pitched great this season - except for one start against the Brewers. That came 2 1/2 weeks ago when he allowed four runs on six hits in 5 1/3 innings in a 9-3 loss to the Brewers. It's his lone loss on the year. Despite that outing, Gray has a 2.21 ERA on the season and a 2.88 lifetime ERA versus the Brewers in seven starts. 
Gray, who has allowed six or fewer hits in 35 straight starts, shouldn't lack motivation in this revenge setting for him. 
Houser is a bottom of the rotation type starter. He's yielded a homer in each of his last three starts and has a 3.72 ERA. He's not in good form with a 5.82 ERA in his last three starts. 
The Brewers may not have their best reliever, Josh Hader, available either since he's pitched each of the last two days.