Although Marlins manager Ozzie Guillen hasn’t completely ruled out using Heath Bell in the ninth inning when the Marlins resume the second half of their season Friday night against the Nationals, the 34-year-old, three-time All-Star knows if he’s going to lock down the closer’s job moving forward, he needs to be a lot better than he was in the first half.

He needs to pitch like he used to pitch in San Diego. So far in a Marlins uniform, Bell (2-5, 6.75 ERA) hasn’t fooled many hitters.

According to fangraphs.com, he’s producing swinging strikes just 5.8 percent of the time. His career average is 9.4.

On Sunday in St. Louis, after Bell blew his major-league-leading sixth save of the season, Cardinals hitters admitted they were sitting on Bell’s fastball because they knew he couldn’t throw his other pitchers for strikes. Bell, who is throwing his fastball at 93.7 mph (he was clocked at 94 mph in San Diego last season), admitted he had trouble locating his breaking balls for strikes in April and even got to the point where he abandoned it. But after he got the feel back for it in May, Bell said he started to use it more and said it’s now working better for him than last year.

Trouble is, it’s not getting many people out. Rafael Furcal slapped Bell’s curveball to left for the game-winning hit Sunday.

“I throw hard, but I’m not a pitcher that can just rear back and throw 96 [mph] and get everybody out,” Bell said. “I’ve got to throw my curveball. I’ve got to throw my two-seam fastball. I’ve got to throw my changeup.

“I’m not going to say anything bad about our catchers, and I’m not going to say anything about our situations calling games. I’m not going to call anybody else out. The thing is I just feel like I have to execute my pitches a little bit more. But I think there’s more to it.”

Catcher John Buck said if Bell is insinuating pitch sequence is what is hurting him, the closer can always shake off what he calls.

“It is his game,” Buck said. “He’s got a head on his neck, so he can shake. Otherwise, if you’re that good of a pitcher, go ahead and throw a strike when I call it.”

Bell said his weight isn’t the reason he has struggled this season. Listed at 6-4, 260 pounds, Bell said he has fluctuated between 255 pounds and 265 pounds most of this season. The Marlins weigh players twice a month according to Bell, who admitted a tight calf kept him off the treadmill for about a week last month and caused him to gain a couple of pounds.

“People are starting to talk, saying I’m overweight or I didn’t come in shape. I’m the exact weight I was last year,” he said. “If you want to be exact, I’m like 264 — the last time I weighed in. That was before the road trip.”

Elsewhere

The Marlins have informed first-round draft pick Andrew Heaney out of Oklahoma State, that they do not intend to sign him before Friday’s 5 p.m. deadline, sources have confirmed.

As the ninth overall pick in the draft, the left-handed pitcher is slotted to receive a signing bonus of $2.8 million, and he did not ask for more than the established figure, according to a source close to the negotiations. But the Marlins offered the pitcher less than $2.6 million, which he rejected.

If Heaney doesn’t sign, he will most likely pitch in an independent league rather than return to Oklahoma State for his senior season. As compensation, the Marlins would receive next year’s 10th overall pick in the draft in addition to their normal draft pick.

• Before Saturday’s game, Jeff Conine and Ivan Rodriguez will perform a reenactment of the game-ending play at the plate in Game 4 of the 2003 National League Division Series. Conine threw out the Giants’ J.T. Snow for the final out. Rodriguez took the throw from Conine and managed to hold on to the ball despite being run over by Snow.

• Reliever Edward Mujica (broken toe on his right foot), who is eligible to come off the disabled list and rejoin the Marlins on Sunday, threw a bullpen session Thursday. Mujica said he might make a rehab appearance in Jupiter either Friday or Saturday.

COMING UP

•  Friday: Marlins RHP Josh Johnson (5-5, 4.06 ERA) vs. Washington Nationals RHP Jordan Zimmermann (5-6, 2.61), 7:10 p.m., Marlins Park.

•  Saturday: Marlins LHP Mark Buehrle (8-8, 3.25) vs. Washington Nationals LHP Gio Gonzalez (12-3, 2.92), 7:10 p.m., Marlins Park.

•  Scouting report: The Marlins are 3-2 this season against the first-place Nationals and swept a three-game series against Washington at Marlins Park in May. … Johnson (8-0) has never lost to the Nats. … Zimmermann has never defeated the Marlins in six career starts, going 0-3.