But the Cardinals called, and Keisler elected to give it another shot. He's still trying to cut it as a Major League starter, and he saw opportunity in St. Louis.
"I'm not getting any younger, so I was going to go and make some money," Keisler said. "Go over there and start, and make some guaranteed money over there. But the Cardinals are the Cardinals, and them giving me a roster spot and telling me that they want me to start, I'm going to take them up on it.
"I don't want to go [to Japan]. I want to pitch in the Major Leagues. I want to be a starter in the Major Leagues. And I feel like I can do that."
Keisler stated his case forcefully on Thursday, pitching three perfect innings in St. Louis' 2-1 win over Minnesota. Keisler hasn't received a start yet, but he's being stretched out and pitching on an every-fifth-day regimen. He's caught the eye of Cardinals manager Tony La Russa and pitching coach Dave Duncan.
Keisler blitzed through his outing on Thursday, starting out with strikeouts of the dangerous Michael Cuddyer and reigning American League MVP Justin Morneau. He made it 3-for-3 by fanning Glenn Williams, then retired the next six men in order as well.
It's the kind of game that Keisler, who is on the 40-man roster but still faces a numbers crunch, knows he needs to have more of. As one of seven or eight candidates for the rotation, he'll have to force his way into the starting five.
"I know that I have to be lights-out every time," he said. "I know that's hard to do, and I'm not going to pressure myself to try to do that, but I'm going to come in with that mentality. I'm giving it all I've got here every time, because that's what it's going to take for me. Nothing is guaranteed for me at all."
Back on the mound: Right-hander Brian Falkenborg made his return to active duty on Thursday after missing a week due to food poisoning. Falkenborg, whose last game appearance came on Feb. 28, allowed a run on three hits in one inning.
"I didn't feel great," Falkenborg said. "I didn't feel like I had a whole lot. But I wasn't out there with my hands on my knees searching for my next breath."
Strange line: Kip Wells allowed six base hits in three innings, but kept the Twins off the board on Thursday. He benefited from a strikeout-caught stealing double play in the first to escape from a jam. In the second, he loaded the bases on three singles before getting a 1-2-3 double play and a strikeout to escape. Another caught-stealing provided an out in the third.
"Obviously, there's stuff to work on every time," Wells said. "Today, I wanted to throw some more changeups and try some front-door sinkers to lefties, and I was able to do a few of those."
Bits and pieces: La Russa said that he expects second baseman Adam Kennedy to play before the end of the weekend. Kennedy is recuperating from a strained oblique muscle. ... Cal Eldred, who will serve as a coach during the spring, made his first appearance in uniform on Thursday. ... Jason Isringhausen will throw to hitters for the second time during Friday's pregame workout. ... Preston Wilson broke out of a slump with a bloop single in his third at-bat on Thursday. Wilson had gone hitless in three starts since sitting out due to biceps tendinitis.
Quotable: "I was able to get myself into a bases-loaded jam and somehow find a way to get out of it. There are times when you're out there with the bases loaded, no outs, and you're thinking, 'There's a lot of ways I can't get out of this.' For me at least, today is an instance that I can hopefully recall and say, 'Well, this is one way you can get out of it.'" -- Wells
Weather report: Warm and windy. The forecast calls for a first-pitch temperature of 79 degrees on Friday, dipping to a still-lovely 76 by the end of the game. Partly cloudy skies may give way to mostly cloudy, with a slight (20 percent) chance of rain and winds around 15 mph.
Coming up: Anthony Reyes and Brad Thompson will both continue to stake claims to rotation spots in Friday's home game against the Marlins. Reyes gets the start in the 12:05 p.m. CT game, with Thompson set to pitch later in the contest. Florida will start Scott Olsen.
Matthew Leach is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.