SAN DIEGO — Keaton Winn has had stretches of success in the big leagues and was one of several Giants to show better velocity this spring. While the opening series against the New York Yankees went poorly overall, Winn threw two shutout innings. There have been signs that he could turn into part of the solution for the Giants bullpen, but you never quite know if a player can handle the late innings until he tries. On Monday, it appeared Winn will be just fine. The right-hander pitched the eighth and struck out the side. He needed just 13 pitches, 10 of which were splitters. In that limited work, he got five swinging strikes on the pitch. “I think him at the back end of the bullpen with that split and the quality of the fastball is going to be a lot of fun,” catcher Patrick Bailey said. The question now for the Giants might be where exactly Winn slots in. After he breezed through the eighth, Ryan Walker gave up a two-run homer in the ninth. Walker ultimately got out of the inning and earned the save, and to be fair, he was the one tasked with facing the top of the San Diego Padres lineup. The damage came from Jackson Merrill, but Walker...