FORT MYERS, FLA. - On glorious days like Wednesday, writers search for synonyms to describe the prescription-glasses-clear, azure, cerulean, cobalt, indigo, sapphire sky that hung over Hammond Stadium.

Synonyms weren't necessary. In the morning, as the Twins began their first full-squad workout, the sky was blue. Really, really, blue. A soft breeze carried hints of sea salt over the fields on another 80-degree day in paradise, and the real work, the art and craft of baseball, began.

After a team meeting, stretching and a game of catch, Twins manager Ron Gardenhire called every infielder in camp to the half field tucked behind the home bullpen at Hammond Stadium. "Time for 'Good Morning America,'" he said, and thus began a drill that is steeped in Twins lore and reflective of all the organization holds dear.

"Good Morning America" is Gardenhire's version of a drill installed and instilled by his predecessor. Tom Kelly, now a special assistant to the general manager, called his version "Rocket-Fire," and used fungo bats and ground balls that raced across the infield like tracers to test and humble his players.

Wednesday, Gardenhire and Kelly coached the infielders while four coaches hit or threw grounders to the players. After five days of leisurely workouts designed to ease pitchers and catchers into their routines, "Good Morning America" shocked the players and their cardiovascular systems like a defibrillator.

After the 1986 season, Gardenhire was traded to the Twins. As an aspiring shortstop, he remembers his first "Rocket-Fire" drill under Kelly in 1987, Kelly's first full year as Twins manager.

"I was involved in that in major league camp as a player," Gardenhire said Wednesday. "That sent me to become a coach real early. 'Rocket-Fire' took me out of commission.

"We kind of tweaked it as it went along, as I became a coach in '91. We tweaked it into Good Morning America, an everyday thing instead of a one-time-a-spring thing."

Infielders are forced to make play after play in rapid succession, facing every possible situation, as Kelly and Gardenhire chatter and critique. "The theory is to get their heart rate up and make sure they can keep their anxiety down at the same time," Gardenhire said. "Under extreme duress, guys panic and it's one of these things that you get a little tired, you get lazy. We want them to slow everything down rather than speed everything up -- and catch the ball."

The '86 Twins finished 71-91. Kelly instituted "Rocket-Fire" in the spring of 1987. The Twins would play exemplary infield defense and win the World Series.

"We kept going until we fell down, or got better," Kelly said. "You found out who could handle the duration, the stamina, the composure end of it.

"What we're looking for is composure under duress. It's also built so that the pitchers, while they warm up, they'll see how hard our players are working on defense, and we hope that will entice them to throw the ball over the plate and give these players a chance to get the out.

"In '87, I saw players who wanted to stop finishing last and thought, 'This guy thinks this is important, let's get after it.'"

Players who arrive in Twins camp from other organizations are often surprised by the intensity of the drill and by the Twins' emphasis on fielding. Kelly is a stickler for proper footwork at first base. Gardenhire obsesses over middle-infield play, particularly the turning of the double play.

So under a really, really blue sky on Wednesday morning, the past and present Twins managers worked their charges like they were drill sergeants and this was boot camp, and Gardenhire began melding an infield that features talent and uncertainty at every position.

First baseman Justin Morneau is recovering from a concussion. Presumed second baseman Tsuyoshi Nishioka, the All-Star from Japan, is adjusting to a new country. Presumed shortstop Alexi Casilla is trying to prove he can play every day in the big leagues. Third baseman Danny Valencia is trying to become the Twins' first long-term third baseman since Corey Koskie left after the 2004 season.

Utility infielder Matt Tolbert has run through the Twins' infield drills since 2008. "At first, I was like, 'Wow, that's a lot of ground balls,'" he said. "I just tried to keep up.

"After you do it a few times, you get used to it. At first, it's pretty tough. You hear TK and Gardy and see them walking around, and so you want to do everything right. It's intense."

Intense by spring training standards, at least. Under the really blue sky and the sea breezes, in the midst of a camp that often resembles millionaire calisthenics, Twins infielders hustle and hone their skills.

"I kinda like it," Valencia said later, as he wiped sweat from his face. "It definitely gets you ready."

Jim Souhan can be heard Sundays from 10 a.m. to noon and weekdays at 2:40 p.m. on 1500ESPN. His Twitter name is Souhanstrib. • jsouhan@startribune.com