But it got the Dodgers a split of their four-game series after Thursday's 4-0 win over the Cubs at Wrigley Field.
"Any time you've got Kershaw and Zack starting and you don't get a win in either game, chances are you'll run into trouble, because it's three days before you get back to them," said manager Don Mattingly. "But Carlos gave us zeros for five innings and the bullpen pieced it together."
Dodgers president Andrew Friedman is stalking rotation upgrades for his minimum-wage subs, but Frias gave his club just enough with five innings despite feeling weak and dehydrated from an early-week bout with the flu.