Parra, who turns 32 in a couple of days, was on a minor league deal in the spring and made the team out of Scottsdale. He had spent the previous three seasons in Colorado. Before that the 11-year veteran did time with the Orioles and Twins. He came up with the Diamondbacks and played there for six seasons. He's a career .278/.325/.405 hitter (92 OPS+). His real value is his ability to play all three outfield positions and to occasionally take a turn at first base, but you have to have some kind of bat if want to stick and Parra hasn't hit for a while.
The Giants have the worst offense in baseball so, yeah, you gotta make a change sometimes.