For every player fans rally behind, for every face of the franchise, there's someone on the other end. A scapegoat. A pariah. They come in all forms.

What makes a player "hated" is hardly universal: bad contracts, poor attitudes, and disappointing performances can all take their toll on an athlete's likability. The only real guiding principle is the better someone plays, the more likely everyone else is to ignore their faults.

However, at the echelon of infamy are the players that find a way to be hated even when they play at superhuman levels. Classic examples include Roger Clemens and, yes, Barry Bonds. Bonds is excluded from this particular line-up, mainly due to the fact that most of the hatred directed at him comes from outside of the fanbase.

What follows are 10 players that, for varying reasons, earned the scorn of the Giants' faithful. The names have not been changed to protect the innocent.

10. Jose Guillen

Jose Guillen will best be remembered for what he didn't do: contribute in any way, shape or form to the Giants' 2010 World Series championship.

Guillen was brought on board in August of 2010 to help bolster a roster making a run at the San Diego Padres for the NL West title. General manager Brian Sabean chose to ignore the outfielder's rather checkered past, which included being suspended in 2004 by the Los Angeles Angels for "inappropriate conduct" directed at manager Mike Scioscia. He also famously tossed a few chairs around the clubhouse while arguing with Royals pitching coach Bob McClure in 2008, among other incidents.

As a Giant, he offered little in the way of offensive assistance. His unremarkable year culminated when he was rather mysteriously left off all the postseason rosters, and was not shown on camera for the duration of the Giants' 2010 postseason run.

It would later be learned that Guillen was tied to an investigation revolving around human growth hormone. He has yet to return to the big leagues. Few, if any, will miss him.

9. Aaron Rowand

I do not hate Aaron Rowand.

To clarify, I hated the way he played on countless occasions. I was thrilled to learn in hindsight that I had attended what would be Rowand's final game as a Giant. Everything about Rowand reeked of the Brian Sabean Band-Aid cure: overpay a veteran coming off an anomaly career year and watch him fail—for multiple years.

Yet, Rowand as a player didn't bother me. He often accepted the demotions handed down by manager Bruce Bochy, and really did seem to believe he was going to mash a homer every time he came up to bat. Except he didn't do that, or much of anything else—and people noticed.

Rowand, signed to a 5-year, $60 million contract in 2007, languished in his new home. His OPS dropped by 100 points, and the leadership role Sabean saw him inhabiting was limited by his poor performance. The Giants would ultimately designate Rowand for assignment in August 2011.

Those who hated Rowand—and there were many—should probably redirect their ire towards a front office that saw $60 million worth of potential in him. Still, his name remains somewhat of a dirty word among circles.

8. Sidney Ponson

When Brian Sabean shipped top prospect Kurt Ainsworth and Damian Moss to the Orioles in exchange for Ponson, the Aruba native seemed like a promising return. Ace Kirk Reuter was headed towards the DL with back issues and the bullpen was breaking under the weight of a weak front rotation.

Instead, Ponson left all his talent on the East Coast. He posted a 3-6 record to go with a 3.71 ERA.

He was also utterly ineffective in his Game 2 start against the Florida Marlins in the 2003 NLDS. He gave up seven hits and four runs in five innings. The Giants lost the game, and eventually the series.

Ponson is hated for the lost talent his acquisition represented. Ponson's career would not get any better, including a proclamation by ESPN's Jerry Crasnick that Sid was "the least valuable pitcher of the 2000's."

7. Orel Hershiser

You never sign your rival's washed-up star. Unless you do.

Orel Hershiser came to the Giants in 1998, having already spent the majority of his career as the poster boy for the Los Angeles Dodgers and later the Cleveland Indians.

Whatever role the Giants' envisioned Hershiser playing for them, the stigma he brought along him vastly outweighed the talents he still possessed. Expecting fans to cheer for a player who thoroughly dominated their team for years was an exercise in futility.

6. Miguel Tejada

Miguel Tejada was doomed from the get-go.

In desperate need of a shortstop after the departures of infielders Edgar Renteria and Juan Uribe, fans eagerly awaited word about who Brian Sabean might get. They never expected him to build a time-machine back to 2002. Clearly that's what Sabean must have done, because had he looked at the Tejada of 2011, he surely would've gone a different route.

Tejada, signed for one year at $6.5 million, was an embarrassment of injuries, errors and poor bat skills. The aged Miggy was a low-point in a batting order filled with mediocrity.

When Brandon Crawford emerged as a viable shortstop in late May, fans boiled over with frustration each time Tejada usurped the rookie as a starter. When yet another injury forced the front office to sign Orlando Cabrera, all hope was officially lost.

5. Jeff Kent

Call him the anti-Orel Hershiser—or just a total jerk.

Jeff Kent, at one point a Giants' fan favorite and stellar second baseman, did the unthinkable in 2004 when he signed a three-year, $21 million contract with the Los Angeles Dodgers.

Even though Kent was already removed from the Giants, having spent two seasons playing for the Houston Astros, the disgust at seeing him arrive in San Francisco wearing Dodger blue was evident from the get-go.

Kent was never a very sociable person, coming to near blows with Barry Bonds during his tenure as a Giant. His disrespect for teammates, coupled with his turn to the dark (blue) side, cemented his status as one of the more hated San Francisco Giants players.

4. Neifi Perez

Neifi Perez was a remarkably terrible player.

When he was signed on June 2003 (his only full season as a Giant), he succeeded in doing nothing right. Perez was the player whose at-bats you scheduled your bathroom breaks for.

Former Salon.com writer King Kaufman—and current writing program manager here at Bleacher Report—went so far as to invent a "Neifi Index," which he explains thusly:

I noticed [Perez] was a sort of secret weapon. The Giants were a good but not great 26–22 on the days when Pérez made it onto the field. But when he stayed in the dugout, they were 13–1. So I invented the Neifi Index, a measure of the contribution a player makes to his team by not playing. The Giants had a .542 winning percentage when Pérez played, .929 when he did not. So his Neifi Index was .387 (.929 minus .542). I concocted the Neifi Award, given to the bench player in each league with the highest Neifi Index.

Perennially disappointing, Neifi Perez has forever left the bad taste of his unremarkable play upon us.

3. Barry Zito

You didn't think we were getting through this list without mentioning Zito, did you?

Barry Zito signed perhaps the worst contract in history in December 2006—at least for everyone not named Barry Zito. From a sabermetrics standpoint, Zito is a colossal disappointment. Each season, angered fans look at his contract and imagine who else could be taking the field in his place.

And yet...he's a good guy. I know, I know, how easy would it be if Barry Zito had a terrible attitude and a criminal record? The fact remains, though, that Zito has taken his lumps—like being left off all of the playoff rosters in 2010—without any public complaint. Every spring training he arrives ready to prove himself worthy of the rotation.

Every year, he fails.

Fans hate Barry Zito as an obstacle to new talent. It's unfortunate, but justified. Until Zito's contract ends in 2013, he will be the most despised man in orange and black.

2. Armando Benitez

In the days before Brian Wilson, there was Armando Benitez.

Signed in 2005 to a three-year, $21.5 million deal, Benitez was coming off a scorching-hot year for the Florida Marlins. He'd put 47 saves into the record books that season.

He'd notch only 45 more in two-plus seasons as a Giant. 

Plagued by a hamstring injury incurred only a month into the 2005 season, Benitez was inconsistent and hot tempered. He often fell to blaming a lack of offense for his team's woes, which would make sense if not for all the blown saves he had (14). 

When Benitez was shipped to back to Florida in 2007, fans were able to breathe a collective sigh of relief. They may still want to charge him for all the ulcer medication he caused them to need.

1. A.J. Pierzynski

There's no sugarcoating this one.

For starters, Brian Sabean grossly overpaid for the Minnesota Twins catcher, giving up Joe Nathan, Boof Bonser and Francisco Liriano. Many would later consider the trade one of the worst in recent memory.

Then there was the player the Giants got in return. A.J. Pierzynski has been universally regarded as one of the most hated players in baseball. He is selfish, egotistical and quick to blame anyone but himself.

The Giants are no strangers to difficult personalities, having fostering the king of them all in Barry Bonds. But Bonds also delivered with his bat, while Pierzynski was mediocre at best. In 128 at bats, he offered a dismal .272 BA to go with 11 home runs and 77 RBI.

Also, there's this story, courtesy of the San Francisco Chronicle. In spring training, Pierzynski was hit by an errant ball in his nether regions. When trainer Stan Conte came to his side and asked him how he was feeling, Pierzynski said "like this" and socked Conte in the groin. The article states there were multiple witnesses to this event, and that it slipped under the radar because all the beat reporters were away doing interviews.

A.J., we hate you.