CHICAGO — Ryan Kalish isn’t supposed to be playing baseball, not after seven surgeries. Once a top prospect for the Red Sox, he had spinal fusion surgery in 2013, and more recently, microfracture knee surgery on both knees, which kept him out of the big leagues in 2015. He began his comeback for this season in the Puerto Rico winter league in November. In mid-February this year, he had signed with the Sioux City Explorers and was ready to play in an independent league. But he returned to the Cubs in early March, was assigned to Triple-A Iowa, and then called up when Matt Szczur was injured. On Saturday, Kalish delivered a pinch-hit two-run single in the sixth that was key in Chicago’s 8-5 come-from-behind win over Washington.