Ryan Garko, 28, is currently .285 with 11 home runs and 39 RBIs in 78 games for Cleveland, including a run of .343 in July which raised his average 25 points. Verdict: it's not the power bat they really need.
Meanwhile, Scott Barnes, 21, considered a Top-20 prospect in the Giants organization, is 12-3 with a 2.85 ERA and 99 strikeouts in 18 starts and 98.0 innings. Remember, however, that's Single-A.
What Giants fans did not want SF to do is trade their top pitching prospects, Madison Baumgartner or Tim Alderson. They also didn't want the Giants to trade top catching (and hitting) prospect Buster Posey. Certainly, they wouldn't have appreciated trading those prospects for Ryan Garko, who's better than what they have at 1B, but not great.
However, Ryan Garko can't become a free agent without the Giants giving up on him. He's eligible for salary arbitration for the first time after this season, which means that the Giants can retain him if they want. His salary is an low, low price of $446,000, though you can expect that to rise with arbitration.