Just about all his new teammates aren't much older than rookies, anyway.
The 29-year-old right-hander took a physical with his new team, and toured Kauffman Stadium on a brisk Monday afternoon, after a trade earlier this month sent him from the Los Angeles Angels to the Royals for a minor league pitcher and some cash to help cover his contract.
"It's like I'm a rookie now," Santana said between meetings. "It's a new team."
Indeed, Santana has been a fixture in the Angels' rotation since 2005, going 96-80 with a 4.33 ERA while starting at least 28 games in eight consecutive seasons - precisely the kind of dependable starting pitching that the Royals have been lacking for close to three decades.
The Angels signed Santana as a free agent in 2000 and helped him develop into a solid starter of 96 games over the past three seasons. And even though he went 9-13 with a 5.16 ERA last season, he was good enough down the stretch to give him - and the Royals - high hopes for next season.
"I'm happy to be here," he said. "Everything's healthy. Everything is ready to go."
That was no sure thing when Santana arrived in Kansas City - there were rumors about potential elbow problems, and a decrease in velocity had caused some trepidation.
Everything has checked out, though, and the Royals believe they have a front-of-the-rotation starter to help solidify a starting corps that was abysmal last season.
"We were able to scout Ervin during the entire year, specifically the second half," Royals general manager Dayton Moore said shortly after the trade. "His August and September were really good. From a statistical standpoint, he was very good."
Santana, who will turn 30 in December, has shown the potential to be a No. 1 starter, winning at least 16 games in three seasons. He threw a no-hitter in 2011 and a one-hitter last season, yet he confounded the Angels with his inconsistencies in 2012.
His resume combined with his raw talent drew comparisons to skeptics in Kansas City of Jonathan Sanchez, the former Giants pitcher whom the Royals acquired last season, and who performed so poorly this season that the team basically gave him away midway through the summer.
Santana said he's spoken at length with Moore, along with Royals manager Ned Yost, and everyone in the organization appears to be optimistic that the hard thrower with the hard slider and backdoor curveball can become a dependable piece of the rotation.
"They called me and told me they're happy to have me," Santana said, "and they can't wait to work with me, and I can't wait to work with them."
Santana said he's also jazzed about working the Royals' collection of young defensive talent.
Alex Gordon recently won his second Gold Glove,
Mike Moustakas evolved into a solid third baseman, shortstop
Alcides Escobar showed tremendous range, and
Eric Hosmer had a good enough year at first base that his defense helped even out his offensive shortcomings.
"It's a young team, a lot of talent, and an aggressive team. They score a lot of runs," Santana said. "To me, it's the same baseball. Nothing's changed. Just coming here to do my job."