"It wasn't mapped out, but I was scheduled to get another injection during the season," Vogelsong said. "[Thursday] was just a good day for it. I'm doing fine, no issues. I'm fine for a 34-year-old."
Giants manager Bruce Bochy verified Vogelsong's health and the pitcher went along with his regularly scheduled bullpen session Friday.
"It's hard to feel better when there's nothing going on," Vogelsong said of his back, which nagged him during Spring Training. "There's nothing to do, I'm not worried about it."
In 33 2/3 innings this season, the right-hander has a 2.94 ERA, with 26 strikeouts and two home runs allowed.
His last outing came against the Dodgers on Tuesday, when he gave up one earned run on eight hits over 7 1/3 innings to outduel Clayton Kershaw.
"At times I felt like I didn't have the best stuff, but I got outs -- that's what pitching is," Vogelsong said. "Obviously, it wasn't just me the other night; the defense helped me out."