Rarely has minding their own business meant so much for either club.
"One thing about it: The next four days, something's got to give," Tigers manager Jim Leyland said.
The Tigers are hoping it's not their lead that gives.
With a two-game advantage, the Tigers are in the position of strength if they get a split from the four-game series. Win two, and they can take their two-game lead with three games to play into the regular season's final weekend. They could then clinch the division if they take two of three from the White Sox that weekend, also at Comerica Park.
But a split is not how either side is thinking going in. They're thinking of this as a winner-take-control showdown to essentially decide a division that the Tigers have led since mid-May but haven't commanded, and the Twins have threatened at times all year but haven't led outright since the season's opening week.
The Twins can leave town with the division deadlocked with three games to play if they take three out of four. On the flip side, the Tigers can clinch the division by winning three of four.
"Both teams control their own destiny. That's basically what it boils down to," Twins first baseman Michael Cuddyer said. "You've got a four-game series, and no matter what happens, that four-game series is going to tell all. Both teams control their own destiny, and that's what makes it fun. It's a playoff series, a four-game playoff series, and it's going to be that type of atmosphere and that type of excitement."
That sense of control is equally evident in the other clubhouse, as one would expect from the team that's ahead.
"I would say it's as close to a playoff game as you can get without actually being in a playoff game," Tigers third baseman Brandon Inge said. "Just go out there and have some fun with it."
The Tigers have displayed that kind of loose attitude the past couple weeks after looking tight at times in August and early September. Leyland has emphasized to his players to enjoy this chase, because so many other teams would love to be in their position.
In that sense, this week should be a blast for them, to have such an important series at home in what should be an intense atmosphere. In other ways, it's arguably a relief, to be able to focus on one game without keeping an eye on another game in another city.
They're coming off a winning road trip in which they rebounded from a rough series in Minnesota to win four in a row and five out of six, a solid stretch from a team that went 2 1/2 months this summer without a series victory away from home.
The problem was that the Twins' current roll made it feel meaningless. Minnesota was on an 11-1 roll before losing to Zack Greinke and the Royals Sunday, and the wins cut Detroit's lead from 5 1/2 games two weeks ago to two games now.
"It's not that we're playing that bad," Leyland said. "We just won four in a row, including one over them. But they've been on a tear. But that doesn't have anything to do with how we play."
Starting Monday, it does, once again.
The fact that the Twins have done all this without Justin Morneau, a noted Tiger killer over his career, is all the more impressive. To Leyland, it's a credit to the Twins organization, which to him doesn't get credit for the talent they've assembled.
"It's been a lot of fun watching us lately," said Twins left-hander Nick Blackburn, who gets the starting nod in Monday's series opener. "We're doing everything right. We're executing pitches, getting guys over and driving them in. It makes it a lot more fun. We're having a blast.
"I feel like there's good confidence right now and even talking to guys during BP, it feels like we are in position right where we want to be."
They have the confidence of knowing they can beat Detroit's front-line starters. They handed losses to both Rick Porcello and Justin Verlander a week and a half ago at the Metrodome. Those two Tigers will start the first two games of the series before Detroit turns to Eddie Bonine and Nate Robertson.
Among them, only Porcello has really found a way to solve Joe Mauer, who's batting .346 (18-for-65) with four homers and 12 RBIs against Detroit this year, including .350 at Comerica Park. He's 1-for-6 off Porcello.
Just about as worrisome now has been Cuddyer, who homered in each of the first two games against Detroit a week and a half ago, and Jason Kubel, batting .383 off Detroit pitching this year.
"Now that we've been on a good stretch, we feel like we have a chance to win every game," Cuddyer said. "We have to win every game. That's basically the mentality we have."
Both Cuddyer and Blackburn think they can. The Tigers, in turn, see the pressure on the Twins to do that, or something close to that. In turn, they'll hope to pressure Blackburn Monday, followed by the same three Twins starters who faced the Tigers a week and a half ago: Brian Duensing, Carl Pavano and Scott Baker.
The Tigers turn to their usual power source in Miguel Cabrera, batting .300 with five homers and 14 RBIs against the Twins this year.
"We have to get wins right now," Cabrera said after driving in four runs in Saturday's comeback over the White Sox.
At Comerica Park, they usually get those wins. Their 48-26 record at home ranks third-best in the Majors behind the Red Sox and Yankees. They took two of three from the Twins in the Motor City in August. But that didn't have nearly these implications.
Come Monday, the postseason has effectively begun.
"To be honest with you, this is the stuff you play for," Inge said. "This is the stuff you practice all offseason for. When you miss time with your family, this is what you play for, to get to the postseason. And these four games coming up, they're the most important games of the year."
Jason Beck is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.