The departure won't be entirely by choice, as Lohse has said often enough that he would welcome a return to a city that has been his baseball home since the start of the 2008 season. The organization, though, has already begun to plan past him, pleased with the starting pitchers it already has locked down for next season. Lohse is set to be a free agent.
So with separation imminent, now it's simply up to Lohse to write his farewell script.
Lohse, who turns 34 on Thursday, has never won a postseason game. Nor is he the most recognizable on this current Cardinals' pitching staff. But he earned the chance to be the go-to guy on Friday -- when St. Louis faces the Braves at Turner Field in a one-game National League Wild Card playoff -- because of the six-month resume he's pieced together this year.
Several weeks ago, the Cardinals lined up their rotation through the end of the year. It was no accident that Lohse's spot fell the day after the regular season ended.
"It feels real good to know that they trust me enough to go out there and pitch in a one-game playoff," Lohse said. "That's something you dream about as a kid. Now I get to go do it. I've had a good year. I feel like I've done everything I could this year to help get us in this position. I'll do everything I've been doing to help win on Friday."
Lohse wrapped up the regular season 16-3, giving him a Major League-best .842 winning percentage. He set a career high with 211 innings pitched and ranked eighth in the Majors with a 2.86 ERA. Only two NL pitchers finished the year with more quality starts than Lohse's 24.
"I think his role on this team has been underrated over the past few years, how much he's really done on the mound for us," first baseman Allen Craig said. "He's been very consistent when he's been healthy. He's going to be great for us."
Indeed, Lohse has been an under-the-radar asset to this franchise long before this calendar year.
He won 15 games in 2008, after which he signed a four-year, $41 million extension to stay. He battled through right forearm issues each of the next two seasons, rebounded to win 14 of his 30 starts in 2011 and then had the best season of his 12-year career in '12.
He's done so, too, with little care about never cracking much of the spotlight, even though he has long been deserving of more attention.
"I prepare myself. I do my work," Lohse said. "I'm not a guy who's going to stand up and say, 'Look at me.' That's not in my nature. I love the pressure. I love all the other stuff that comes along with pitching in a big game. I'm not out there to tout myself. I'm not out there saying, 'Look at my numbers, I should be looked at as something different.' I do my job, and these guys know I keep them in the game."
In order to ensure that Friday will not be his last game in a Cardinals uniform, Lohse will have to right his previous postseason wrongs. He'll enter 0-4 with a 5.54 ERA in nine previous playoff appearances (four starts). He allowed 11 earned runs in 12 2/3 postseason innings last year.
Lohse will also have the task of facing an Atlanta offense that knocked him around for five runs and nine hits in a five-inning start back in May.
"That was kind of a turning point for me that month," Lohse said. "I figured out some things that I did incorrectly that game. I'll make the adjustments I need to make and go out there and have a good plan."
Indeed, that May 30 game proved to be a pivotal point in Lohse's year. The Mets' R.A. Dickey was the only NL pitcher to post a lower ERA from that point on through the end of the regular season.
Beginning with his first start in June, Lohse won nine of his next 10 decisions and made 10 straight quality starts. There was hardly any cooling off late in the season either, a testament to the consistency that has come to define Lohse's season.
"This guy, since he's been with us ... he's been one of our best pitchers that goes out there every fifth day," said Chris Carpenter, who pitched -- and won -- two elimination games for the Cardinals in the 2011 postseason.
"He deserves this game. He deserves the chance to go out there and take it on. I've become close with him and he's able to take that pressure. He's able to handle that responsibility. And I know he's going to be looking forward to it. I'm excited about watching him go out and pitch."
Jenifer Langosch is a reporter for MLB.com. Read her blog, By Gosh, It's Langosch, and follow her on Twitter @LangoschMLB. This story was not subject to the approval of Major League Baseball or its clubs.