"Pittsburgh is the only place I wanted to be, and when the opportunity arose I jumped at it," Karstens said Thursday, shortly before taking the Bob Friend bullpen mound for his second side session of Spring Training. "There was no secret that this is the one place I wanted.
"I understood they had to do what they had to do," he added, referring to the considerable amount of wheeling-and-dealing by the Bucs before general manager Neal Huntington finally came calling. "At the same time, they probably knew that if the opportunity arose for me, I'd probably take it. So it's just one of those things that for them and for me, it worked out for both sides."
In truth, it's a work in progress. Karstens is in a long line of candidates for the two spots in the back end of the rotation. But he is a candidate the staff knows and respects.
"He is one of the guys we're looking to give the ball to. We're confident when Jeff is in the rotation and takes the ball," manager Clint Hurdle said. "We'll give him every opportunity to break [camp] in the rotation and go with us. It is what it is -- the entire industry had an opportunity to come and grab him -- he still felt best to come back here."
The rest of the industry shared the Pirates' main misgiving, and a big factor in the decision to non-tender Karstens on Nov. 30: The injuries which limited him to 90 2/3 innings in 2012, and other questions about the durability of a guy whose Major League workload has maxed out at 162 1/3 innings.
"Still, you always have options," Karstens said, reflecting on his stealth free agency. "But it's a matter of comfort level: This is the best situation for me and my family."
Also the best possible situation for all the fans who were in mourning while Karstens was on the loose. He is still trying to crack double-figures in wins for the first time, but is already a favorite and superstar in the eyes of fans, for his ease in connecting and empathizing with them.
Karstens was well aware of the sentiments.
"I always got a sense of that but, at the same time, you don't want to make it awkward for the team," he said. "But I do truly appreciate all the support I have."
And he reciprocates. Perhaps no one in the Pirates clubhouse got a bigger buzz out of the jaunty months of June and July than Karstens, because he saw smiles on the faces of fans whose chins had dragged through a 105-loss season only two years earlier. He openly talked about how much that meant to him -- as he now talks about embracing the opportunity to contribute to trying to finish it off.
"Oh, without a doubt," Karstens said. "I was here when we lost 100 games, and to do something special in Pittsburgh is going to mean that much more. With the critics always doubting us, it's time to put an end to it, get in our 'I told you so.' Of course, stuff like that doesn't happen overnight. But just to be with all these guys, everything we've been through."
No one has been through as much of it as has Karstens. Those 105-loss Pirates of 2010 did already include the now-grown-up core of the team (Andrew McCutchen, Neil Walker, Pedro Alvarez and Garrett Jones, among others). But Karstens has played under the Jolly Roger since 2008, the only Pirates player left from that club.
Those '08 Bucs did have a Marte -- but it was Damaso, the left-handed reliever, not current left fielder Starling Marte.
A swing man throughout his career, Karstens a year ago went through his first Spring Training locked into his team's rotation. The gratification did not last long: He had to leave his third start, on April 17 in Arizona, after one inning with inflammation in his pitching shoulder. He did not resurface until late June, and on-and-off hip issues dogged him down the stretch.
"That was the biggest question," said Hurdle, conceding the durability issue. "But we're more than happy to bring him back, because of what we've seen from him. When he's on the mound, he competes well and gives us a chance to win. And he's very optimistic about his health, after the offseason program we'd put in place."
"The biggest thing is that I started earlier," Karstens said about his conditioning. "I feel good. I see no reason at all not to be able to do what I want out there."
And, just think, after all, he'll be able to do it where he wants to.