Jose Pirela has 12 batted-ball events against lefties in August with an average exit velocity of 94.9 MPH. Pirela has 3 extra-base hits against lefties this month and 7 homers on the season, so there is a little bit of power potential for him in good matchups.
Pirela and the Padres will see at least four lefties these week, with Matt Moore and Ty Blach of the Giants being the two easier matchups, and Clayton Kershaw (returning from the DL) and Rich Hill being the opposite of easy. Pirela's $3,300 price tag will be prohibitive for most DFS players, but is definitely worth a look as a contrarian option.