PHOENIX -- Playing in only his 400th Major League game on Monday, Giancarlo Stanton hit his 99th and 100th career homers, lifting the 23-year-old into some rare air.
Stanton joined Bob Horner and Eddie Mathews as the only players in MLB history to make their big league debuts before their 21st birthdays and then hit at least 100 homers in their first 400 games. Age distinction aside, the outfielder became the ninth player and the first in franchise history to accomplish the feat. Ryan Howard and Ryan Braun are the only other active players to have done it.
"It's remarkably how quickly he's done it," Marlins manager Mike Redmond said. "We all played with Mark McGwire, Sammy Sosa, Barry Bonds, but I don't think I've ever seen someone hit a ball harder than he does. He truly crushes the ball, it's pretty amazing. It's a big milestone for such a young guy."
Caught up in the game, Stanton didn't realize until after the Marlins recorded the final out in Monday's 3-2 win that he reached the milestone. So when Redmond handed him the game ball, it caught him off guard at first.
"That was really cool," Stanton said. "I knew I needed seven to start the season, but I lost track."
Jennings feeling at ease back in big leagues
PHOENIX -- Reliever Dan Jennings appeared in 22 games for the Marlins last season over several brief stints with the club. But even though he experienced plenty of success -- allowing four earned runs in 19 innings (a 1.89 ERA) -- he never really got comfortable in the Majors. He was always looking over his shoulder, afraid if he made any mistakes he'd be sent down again.
So after missing out on an Opening Day roster spot, Jennings began 2013 at Triple-A New Orleans, where he worked on his mental approach. He wanted to make sure that when he got another shot with Miami, he'd be ready.
Now 11 appearances into his second big league season after being called up on May 27, Jennings has been fantastic for the Marlins, surrendering only one run over 11 2/3 innings while striking out 10.
"A lot of it is having confidence in yourself and the people around you having confidence in you," Jennings said. "Because once you know that, you can start to build off it. The coaches are sending you out there for a reason, so you just try to take that and run with it."
While Jennings added that sometimes it's good to feel some pressure, he noticed that when he put too much of it on himself, he wasn't being aggressive enough attacking hitters.
"I found I was being really tentative," he said. "You can't pitch that way, you have to know every single pitch you throw is the right one. A lot of it is mental, it's about going out there and pitching with authority."
Jennings has certainly done that in 2013, as none of the six walks he has issued have resulted in runs.
"He's been good, he's done a nice job every time we've put him in there," Marlins manager Mike Redmond said. "He's throwing strikes, and in the big leagues, that's what you need in your relievers."
So where is Jennings' confidence level now compared to last season?
"I'm feeling like I did in Triple-A last year," he said. "Basically I'm pitching care free. I know this is where I'm supposed to be. I'm not tip-toeing around anymore."
Hechavarria doing work with the glove at short
PHOENIX -- Batting only .214 this season, Marlins shortstop Adeiny Hechavarria hasn't been a standout in the club's lineup in 2013. But that hasn't stopped him from making his impact felt in the field.
Entering Tuesday's 3-2 loss to the D-backs, Hechavarria was tied for third in the Majors among shortstops (with the Cardinals' Pete Kozma) in fielding percentage at .990, trailing only Colorado's Troy Tulowitzki and Boston's Stephen Drew.
"No matter what he hits, his defense is important us. We all know his bat is a work in progress, but you see glimpses of how good this kid is going to be when his bat comes along," Marlins manager Mike Redmond said. "He's been a solid defender out there for us. Not a lot of people talk about how consistent and good he has been for us all year."
Hechavarria's fielding prowess was on display in Monday's 3-2 win at Chase Field when made two stellar plays in the first two innings, one snagging a short hop off a line drive, and the other ranging up the middle and throwing out the speedy Gerardo Parra to save a run.
"He has a lot of weapons," Redmond said. "To see his range and to see how easy he gets the ball and makes good throws, it's great. I'm happy with his effort, he is fun to watch."
The 24-year-old went 2-for-3 with an RBI single on Tuesday, but he also made a crucial base running error in the seventh, getting thrown out at third after trying to stretch a leadoff double into a triple.
"A little too aggressive for the situation," Redmond said of the play.
• The Marlins have agreed to terms with seven of their top 10 picks from the 2013 First-Year Player Draft, with the exceptions being first-rounder Colin Moran, Matt Krook (supplemental first) and Trevor Williams (second rounder). Moran is currently playing in the College World Series with North Carolina and Miami won't begin serious contract negotiations with him until after UNC's season ends. Moran went 3-for-5 in UNC's elimination game win over LSU on Tuesday.
• Juan Pierre's 13-game hitting streak entering Tuesday was the outfielder's 10th such streak of his career, tying him with Jose Reyes for the seventh most 13-plus game hitting streaks among active players. He extended it to 14 with a third-inning single.
Tyler Emerick is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.