Ah, spring training. When all 30 teams are still contenders.

“Everybody’s excited,” Redmond said in Jupiter. “Obviously, we’ve got a tremendous opportunity for guys in this camp and I think everybody realizes that. It’s a fresh start.”

From a chilly and damp Phoenix, Ariz., to balmy Kissimmee, Fla., pitchers and catchers for 10 teams reported to training camp Monday, taking physicals, meeting new teammates and, in some cases, managers and coaches.

The pop of fastballs in mitts, they could be heard, too.

Many eager players have been working out “informally” for weeks on minor league fields — position players don’t report for several more days, and all teams will be in full swing by the weekend.

In Tampa, Fla., Yankees captain Derek Jeter ran on a treadmill for the first time since breaking his ankle on Oct. 13, a big step toward reaching his goal of being in New York’s opening day lineup on April 1 against Boston in the Bronx.

In his third week of baseball activities, Jeter was on the infield grass fielding groundballs and in a batting cage taking swings — all while dozens of autograph-seeking fans lined up outside the Yankees’ minor league complex down the road from the big league facility.

“I feel fine,” Jeter said. “I was able to do everything else. I just had to be careful with my ankle, but now I’ve gotten the green light with that. I’ve gotten all the green lights I need.”

In Fort Myers, Fla., Red Sox principal owner John Henry put to rest reports that he was considering selling the franchise.

“You just don’t get an opportunity to own something like the Boston Red Sox. As long as we can do it, the three of us are committed to being here,” Henry told reporters, while acknowledging team president Larry Lucchino and chairman Tom Werner. “These thoughts that we’re somehow selling, those are just not true.”

With a new manager, John Farrell, replacing Bobby Valentine after one disastrous 69-93 season, Henry likes Boston’s chances.

“I would say, especially in comparison to last year, I should be optimistic,” Henry said.

In Kissimmee, Fla., the Houston Astros began their first day in the bruising AL West. One of the most inexperienced teams in baseball will wear fiery orange practice hats and jerseys that evoke the orange rainbow stripes of a better time for an organization that lost over 100 games each of the past two seasons.

“We’ve talked about change throughout the organization, from the time (owner) Jim Crane has taken over the ball club and all the hires he has made,” first-year manager Bo Porter said. “This year (the uniform change) kind of sets the tone because they visually see things have changed. And when you realize that things have changed, you first realize that they’re never going to be the same.

Also hoping for a clean start, Bartolo Colon is back with the Oakland Athletics after serving a 50-game suspension for a positive testosterone test. He had little to say crossing a damp practice field in Phoenix after a 90-minute exam but he’s excited to be with a team that won the AL West in thrilling fashion last year, rallying over the final 10 games to grab the title from the Texas Rangers.

Manager Bob Melvin isn’t worried about Colon getting right back in the flow with his teammates.

“He fit in very well here before and I see that being the same case,” Melvin said. “He knows most of these guys and they all liked him very much and got along with them all and actually was a nice little resource for our younger starters. So, I don’t see any problems there.”

As his teammates reported to Cardinals camp in Jupiter, Fla., Chris Carpenter told media in St. Louis he he’s not ruling out pitching again — even this season.

Last week, the Cardinals said the 37-year-old former ace almost certainly won’t pitch in 2013 and that his career is probably over after a recurrence of a nerve injury that cost him most of last season.

“Maybe I don’t ever want it to end,” said Carpenter, the 2005 NL Cy Young Award winner. “I don’t think I’ll ever retire, to be honest with you. I’ll never say that word. There might always be hope. Maybe like when I’m 48 I can come back and pitch some more.”

In Scottsdale, Ariz., Diamondbacks manager Kirk Gibson greeted his team with a new determination — one that could be mimicked all around the league.

“I’m just determined,” he said. “I can just say that 81-81 (last season) does not sound good to me at all, and then I took it very personally, and I take responsibility for it.”

Added Gibson: “In 2011, we overachieved. In 2012, we underachieved. We want to overachieve again.”