The San Diego Padres dropped Tuesday's game against the Chicago Cubs, 8-3, behind a so-so start from right-handed pitcher Walker Buehler. Buehler wasn't able to complete five innings, pitching a total of 4.2 frames while allowing two runs, three hits and three walks. While the start wasn't the worst from Buehler this season, it continued his struggles early in his Padres tenure. San Diego is about to get some pitching reinforcements very soon, and if Buehler doesn't pitch better soon, he may not have very many more opportunities. Griffin Canning and Lucas Giolito, who the team recently signed from the free agent market, could join the big league club soon. When that happens, the Padres will have some difficult decisions to make. One of them could involve Buehler, who knows he needs to be better. "Just not good enough," Buehler said of his start. "Got to get deeper and get more efficient. I think we’ve kind of established that the stuff has improved, and I’m in a lot better spot.…