The San Francisco Giants already have one of, if not the best catchers in the game, so there likely won't be a whole lot of playing time to go around behind the dish. Regardless, the club needed to add a third backstop to the 40-man roster as they only had two when the day began in Buster Posey and Trevor Brown. Andrew Baggarly of the San Jose Mercury News says that the Giants plan to use Hundley as Posey's primary backup when opening day arrives which will push Brown to Triple-A Sacramento where he will get regular playing time.
Hundley has spent every year of his big league career in the NL West, debuting in 2008 with the San Diego Padres before being traded to the Colorado Rockies in 2014. Last season with the Rockies, Hundley accrued an 82 wRC+, which was a sharp drop-off from the league average 103 he put up in 2015. Either way, he should represent an offensive upgrade over Trevor Brown, who put up a 77 last year.
Of course Hundley out-homered Brown in 2016, 10 to 5, at least partially due to the thin air in Colorado with some extra room given because of an additional 133 plate appearances by the 33 year old. Their walk and strikeout rates are relatively similar, too. Brown holds an ever-so-slight edge defensively according to FanGraphs, and is not quite as bad on the bases, but they have nearly identical ratings of -1.7 (-1.8 for Hundley), which is to say that neither is a good option to have as a lead runner.
The addition of Hundley also gives some wriggle room just in case neither Jarrett Parker nor Mac Williamson claims the left field job this spring, too. If neither is cutting the mustard, Bruce Bochy could, in theory, move Brandon Belt out to left on occasion and have Posey at first base with Hundley behind the dish and Trevor Brown as a third option. If this ends up being the case, the team will have some big issues to worry about, but the addition of Hundley does allow for this to be an option.
In my brief time in the Rockies clubhouse at the end of the season last year, Hundley seemed like the kind of guy that will fit in great in the Giants clubhouse. He was joking around with the media and just seemed to have a leadership quality about him--not that the Giants need any more leaders in their clubhouse. This signing is a nice, small upgrade that has become such a Giants move in recent seasons.