JUPITER, Fla. -- The first bit of advice for any young pitcher is there are going to be growing pains.

It's inevitable, especially on a young Marlins staff.

Former big league left-hander, Al Leiter discussed some of the points to pay attention to with young pitchers on Monday morning. Leiter, a former Marlin, was in town on assignment with MLB Network.

"The safest way to proceed with young pitchers is that, the psyche and the mentality is very fragile," Leiter said.

The Marlins revamped their roster and rotation by a number of offseason trades, including dealing Josh Johnson and Mark Buehrle to the Blue Jays.

"The picture that's painted from the outside is, it's not going to be a very good year, based on what they did this winter," Leiter said. "That's not like, 'Red Alert.' You've got to buy into them. You've got to see and trust that they're going to struggle. And the bumps are going to be -- inconsistent with command.

"If their stuff gets worse, then that's a red flag to be concerned. But if stuff is good, each and every start, if you can build on something that they did within the game that made mistakes. Whether it was in critical times during the game, and there was an opportunity to maybe pitch around a guy, pitch backwards to get to a lesser hitter."

In other words, build on the positives and dissect the negatives, pinpointing how to polish things up.

The bottom line is, the best teacher is experience. And sometimes the numbers won't tell the whole story.

"You can only learn that on a big league mound, in a big league setting and experience," Leiter said. "If you have a 5.00 ERA, oh well. You want the 3.00. But I would say, as a staff, as a pitching coach, as a manager, as a front office, you look for the guys with the plus stuff."

Marlins add Diaz as potential righty bench bat

NYY@HOU: Diaz hits RBI single to put Yankees on top

JUPITER, Fla. -- Throughout his career, Matt Diaz enjoyed great success against Marlins pitching. The 35-year-old outfielder is a career .360 hitter with 10 homers in 66 games against Miami.

After years of seeing what he could do to them, the Marlins now are about to find out what Diaz can do for them.

On Monday night, Miami reached an agreement with Diaz on a Minor League contract with an invitation to Spring Training. He will be in camp on Tuesday, and is expected to be in uniform when the Marlins face the Nationals at Roger Dean Stadium.

Diaz, primarily a corner outfielder, was released by the Yankees on March 17.

Although Opening Day is a week away -- April 1 at Washington -- Diaz will be given a quick look to see if he can make the club.

This spring with the Yankees, the veteran backup outfielder was 6-for-30 (.200) in 13 Grapefruit League games.

Diaz appeared in 51 games with the Braves last year, batting .222 with two home runs and 13 RBIs.

The Marlins are seeking a right-handed bat off the bench to complement the left-handed-hitting Greg Dobbs.

Diaz is a career .324 hitter against left-handed pitching.

The Marlins are still rounding out their roster, and they are exploring players who are being released to see if they are a possible fit.

On Saturday, the Marlins signed utility infielder Wilson Valdez, who was released on Friday by the Giants.

Diaz broke in with the Rays in 2003, and he played in 2005 for the Royals. His greatest success came with the Braves.

Diaz attended Florida State University, and he is a .291 career hitter with 45 homers.

Redmond considering Polanco for cleanup spot

DET@MIA: Polanco discusses his injury, role in lineup

JUPITER, Fla. -- Taking a page out of the Joe Maddon playbook, Marlins manager Mike Redmond is considering making unconventional lineup decisions.

Redmond is seriously considering using established situational hitter Placido Polanco in the fourth spot, behind slugger Giancarlo Stanton.

In Polanco, the Marlins are sacrificing classic power for contact.

"It's one of those things where we're going to have a lot of different guys hitting in probably a lot of different spots," Redmond said. "I like Polanco hitting there. He gives you a veteran bat, a guy who puts the ball in play. He can hit behind runners, he can hit and run. He handles the bat well. He might be a nice fit behind Stanton."

Without a prototypical power option, Redmond is thinking outside the box. He's weighing moves that you regularly see from Maddon, the Rays manager known for going against traditional thinking.

For most of Spring Training, Polanco has batted second, where he has by far had the most experience.

"My approach will be the same," Polanco said. "I don't think they will expect me to hit home runs because I'm hitting fourth. It's just something they had in mind, and they are trying now. That's what Spring Training is for, to try different things. If it works, it works. If it doesn't, we'll go back to whatever he had in mind."

Polanco is used to batting pretty much anywhere. He recalls in his first MLB game, when he was with the Cardinals, manager Tony La Russa had him hit ninth in his first game.

"I've seen a lot of things in this game," he said. "Nothing really surprises me."

Polanco has appeared in the fourth spot in the lineup in just nine games in his career, and he has seven at-bats in the spot. The last time he batted fourth was in 2002.

Polanco has 103 career home runs in 1,809 games.

What he offers is a good situational presence if teams are looking to pitch around Stanton.

"If they're going to pitch around him, at least we know we've got a guy who can put the ball in play, and he can drive in runs," Redmond said. "Sure, it's not going to be via a home run. It's going to be a professional at-bat, and a guy who can keep the line moving."

Donovan Solano is the leading candidate to bat second. So the top four batters are shaping up to be Juan Pierre, Solano, Stanton and Polanco.

Worth noting

• Solano took 30 swings in the batting cages on Monday morning. Out since last week with a tight back, Solano said he hopes to play in a few Grapefruit League games this week in preparation for Opening Day on April 1 at Washington.

Solano could play in a Minor League game in a day or two, and the aim is to have him return for the Grapefruit League finale on Thursday against the Cardinals.

• Top prospect Jose Fernandez struck out nine batters in four innings last Friday in a Double-A exhibition against the Mets. Fernandez threw just 65 pitches in his dominating performance. Fernandez is ranked seventh on MLB.com's Top 100 Prospects list. He is scheduled to pitch again on Wednesday in a Minor League game.

• The Marlins signed catcher Koyie Hill to a Minor League contract, which doesn't include a big league camp invite.