Miami, 16-7 in May, dropped back-to-back games for the first time this month, and on Friday, will turn the ball over to Josh Johnson, who has put a rocky start behind him.
Johnson will be opposed by Tim Lincecum in a matchup that features two premier arms who did not start the season as planned.
While Johnson has thrown well recently -- allowing two runs or fewer in three consecutive quality starts and tossing seven innings in each -- he does have a 4.82 ERA and a 1.51 WHIP, and opponents are batting .301 off him, the fifth-highest mark in the National League.
The righty can see the positives in his most recent outings, however, and believes he is inching back to being the pitcher that posted a 1.64 ERA over nine starts in 2011 before being shut down for the season in May with shoulder issues.
"I'm closer," Johnson said. "My last bullpen was good. We're getting there for sure. It's not quite there. It's just a few very small mechanical things, but my hands are right where they need to be, so that's the good part.
"I'm not trying to muscle anything up, just letting it go and having a little more fun out there."
Lincecum is trying to put his early-season struggles behind him, too, and Johnson expects him to do just that.
"The guy's a proven winner," Johnson said. "He'll turn it around."
The Giants have been waiting for that all season.
Lincecum is 2-4 with a career-worst 6.04 ERA -- only Atlanta's Mike Minor has a higher mark in the NL among qualified starters -- and he has allowed four runs or more in six of his nine starts. The once-hard-throwing right hander, whose average fastball velocity has dipped under 90 mph for the first time in his career, has gone seven innings just twice after logging 210-plus innings in four straight seasons.
In his previous start, Lincecum threw a wild pitch in a rough fourth inning that led to a home-plate collision with the A's Collin Cowgill. Lincecum stayed in to finish the inning, but was removed for a pinch-hitter in the bottom of the frame after 90 pitches in four innings.
"I just hyperextended my thumb in my catching hand, nothing bad," Lincecum said after that start.
The one thing that has been consistent with Lincecum's past has been the strikeouts, despite his drop in velocity. Lincecum is striking out more than 10 batters per nine innings, which places him among the top five in baseball, and he is on his way to another 200-plus strikeout season after averaging 244 over the past four years.
Like Johnson, Giants manager Bruce Bochy believes that Lincecum, who hurt his left thumb in his last start, will snap out of his funk soon.
"Every time he goes out there, I think he's going to have a nice game," Bochy said. "He's so close to doing that."
This will mark the first clash between Johnson and Lincecum.
Marlins: Stanton continuing hot month
Giancarlo Stanton hit his NL-tying ninth homer of May, and 10th of the season, with a blast that traveled an estimated 434 feet off Ryan Vogelsong in the second inning of Thursday's 14-7 loss.
Stanton, who didn't hit his first home run until his 20th game of the season, has not gone more than four games in May without hitting one. The 22-year-old has also 23 of his 32 RBIs during the month.
He will take a five-game hitting streak vs. the Giants, in which he has four homers, into Friday's matchup against Lincecum. Stanton has also reached base safely in all 14 career games against San Francisco.
Omar Infante, who missed three games at the beginning of the week because of a death in the family, collected his second four-hit game of the season on Thursday.
Infante increased his average to .340 and his OPS to .936, both of which are the top marks among all Major League second basemen.
Giants: Cabrera on fire
Melky Cabrera continues to shine in his first year with the Giants.
The 27-year-old extended his hitting streak to eight games by going 3-for-5 in Thursday's blowout win over Miami. He had two doubles, three runs and a season-high four RBIs.
Cabrera recorded his 22nd multihit game of the year and 67th hit in total, both which are tops in the Majors.
He's batting .500 (17-for-34) over the hit streak, tallying multihit games in five of them. On the year, Cabrera is hitting .362 -- trailing only David Wright in the NL -- and sports a .928 OPS.
Buster Posey is forming a potent middle-of-the-order tandem with Cabrera.
After going 2-for-4 on Thursday, Posey is batting .382 over his last nine games after struggling to start the month of May.
The 25-year-old Posey increased his average to .306 and OPS to .859.
The Marlins could set a club record by winning their 17th game of May in Friday's contest. Their most wins in any month is 19, which occurred in August 1997.
San Francisco has won nine of its past 13 games and scored a season-high 14 runs in Thursday's victory. It was the largest margin of defeat in the four games the Giants and Marlins have played this season, after each contest was decided by one run in their first meeting of the year.