Their biggest challenge to winning the National League West is the enemy within.
The Giants have six players that I view as All-Star caliber: Pablo Sandoval, Buster Posey, Tim Lincecum, Matt Cain, Madison Bumgarner and Brian Wilson. For the Giants to contend in 2012, they cannot afford major regression or serious injury to those players.
Unfortunately, major injury and regression have already struck half of those players, as well as their starting second baseman, Freddy Sanchez. Sanchez is out indefinitely with a shoulder injury that cost him most of last season as well.
Wilson is out for the year after undergoing a second Tommy John surgery on his right elbow, Sandoval is lost for the next month after undergoing surgery to remove his left hamate bone one year to the date of having surgery to remove his right hamate bone, and Lincecum is just plain lost.
The good news is that, while Wilson won't return this year, the Giants have a deep enough bull-pen to withstand that loss and, unlike Wilson, Sandoval will be back within the next four-to-six weeks.
The bad news is that there is no timetable for Lincecum to figure out his issues, an unacceptable development for a team build around it's starting rotation.
It isn't all bad for Lincecum right now. He's pitched noticeably better at times during his last four starts after getting lit up by the Colorado Rockies at Coors Field in his second start, culminating in eight excellent innings against the San Diego Padres two starts ago.
His 3.42 fielding independent pitching (FIP) is well below his 5.68 Earned Run Average (ERA), suggesting that Lincecum has been the victim of some bad luck, while his left on base percentage of 60.8 percent is well below his career average of 75.4 percent, also suggesting that bad luck and poor timing are a major culprit for his early struggles.
However, even if Lincecum starts to experience better luck, there are clear signs that he has peaked and is no longer the dominant ace he once was.
During his Cy Young reign in 2008 and 2009, Lincecum led all starters in wins above replacement (15.5), strike-outs per nine innings (10.47), ERA (2.55), FIP (2.48) and home-runs allowed per nine innings (0.42).
Since winning his second Cy Young Award, Lincecum has regressed in all of these categories. During the last two seasons, he has gone from being the best pitcher on the planet to something more human.
The Giants won the World Series with this more hittable version of Lincecum in 2010, but they could not afford any further regression this year if they hoped to get back to the promised land. Unfortunately, Lincecum isn't trending back towards his Cy Young seasons. Instead of getting better, he is getting worse.
His fastball velocity continues to go in the wrong direction, from a high of 94.2 miles per hour (MPH) when he first entered the league all the way down to an average of just 89.8 MPH this season.
Increased command has not come with taking velocity off the fastball. His command peaked in 2009 when he walked a career low 2.72 batters per nine innings, but it has worsened every year since, with his walk rate all the way up to 4.83 per nine innings so far this season, fourth worst in the league.
The combination of below-average velocity and command has made the best pitcher on the planet turn into a giant question mark.
With so few miles per hour now separating the fastball from his vaunted change-up, hitters no longer look as foolish against the disappearing off-speed pitch that made him so dominant.
With Sandoval hurt, Sanchez out indefinitely and Wilson down for the year, the Giants need their starting rotation to anchor the team with their once outstanding ace to carry the team again. Unfortunately, when Tim Lincecum reaches back, it just isn't there right now.