JUPITER, Fla. -- Kennedy. Eckstein. Miles.

It's fitting their names, sticking out in white on bold red backgrounds on their Cardinals jerseys, hang side by side above their tiny infielder gloves in the St. Louis clubhouse at Roger Dean Stadium.

The three of them might as well store their equipment in the same space -- they will be depending on one another a great deal this season. After all, the trio, known for making tough defensive plays, combines to form a nice trifecta in the middle infield for the Cardinals, who know they will need the defense that helped carry them to the World Series last year.

"To me, defense is almost everything," Cardinals infield coach Jose Oquendo said. "We've got a good pitching staff that keeps the ball on the ground. Every day we talk about it and we practice those double plays. We have to prepare for when the ball is hit, to turn it."

In 2006, David Eckstein and Aaron Miles formed the core of the middle infield for the World Series champions. Eckstein started 123 games at shortstop, while Miles started 71 games at second and 31 games at short. Now, with the addition of free-agent signee Adam Kennedy, who began his Major League career as a Cardinal, the Redbirds have three proficient middle infielders.

World Series MVP Eckstein, who made just six errors last season, of course will be back at shortstop, and he'll be reunited with Kennedy, who made nine errors in 139 games at second base for the Angels in 2006. Kennedy will take over at second base, with Miles (17 errors) ready to fill in at any moment in either position.

"The responsibility up the middle is a big one, and we take pride in that being the case," Kennedy said. "The pitcher needs to be able to depend on the double play."

Oquendo said the three know the game, prepare well and understand the importance of defensive and double plays.

"We've been blessed with guys who've given us everything they've had to defensively, and they know their roles and play their part," Oquendo said. "In the past, we've had guys like Tony Womack, Mark Grudzielanek ... look at the job they did for us.

"No matter what year, defense is the No. 1 thing to me. Defense is the most important thing out there. And they have to know that when we're working on defense, it's all about defense. When we're done, they concentrate on whatever else they have to do, offensively or on the bases."

Oquendo pointed out that even though Albert Pujols, the end receiver of the double play, is a tremendous hitter, he practices just as hard at the defensive game at first base to help the club.

Eckstein and Kennedy certainly have a good history. They both won World Series rings in 2002 with the Angels. Kennedy hit three home runs in Game 5 of the American League Championship Series in 2002 and was named the MVP of the ALCS. In 2006, Eckstein became the first National League shortstop and third Cardinal (Bob Gibson in 1974 and 1967 and Darrell Porter in 1982) to win the World Series MVP.

Kennedy said the three are on the same page as far as working together and that each of them has his own style of play.

"You understand the feeds that each one gives to you is just a little different," Kennedy said. "But they're both good athletes and make it simple on me."

Miles doesn't expect to get as many at-bats as last year (426), but he expects to be used a lot at second and short in important situations and late in the game. He certainly has earned the confidence of his manager Tony La Russa.

"It's a real asset to have a guy that can play second and short like [Miles]," La Russa said.

"These two are the starters, and I imagine if I get a little more success, I'll get a start here or there," Miles said. "Throughout the course of the season, guys get tired and guys get sore, and that's an opportunity for me."

Kennedy said it has been easy for him to get comfortable with the other two, both on and off the field, and they often joke with each other.

When Miles was asked if he was impressed with the way the middle infield was shaping up, Kennedy, in earshot, said "I'd better leave for this," and patted Miles on the back as he went to shower.

If history is any indication and they continue to gel on the field like they do in the clubhouse, Cardinals fans are in for some very smooth turns around second base this season.