Willson Contreras' pulled right hamstring comes in the 18th week of the season, with the lead the Cubs took over from the Brewers on July 26 available for the taking.
The Cubs went on a run after the All-Star break, winning 14 of 17 and looking like a team that could shake off its underwhelming first half to win at least 90 games, maybe even 95. But the Cubs just dropped two of three to the Giants in San Francisco after doing the same against the Nationals and D-backs at Wrigley Field.
Chicago is only five games over .500 and on pace to win 85 games, and now St. Louis is playing the best in the Central. The Cardinals continue to shuffle lineups looking for ways to score more runs, but they have gone 25-16 since June 25.
Believe it or not, that's better than every team in the Major Leagues except the Dodgers. The rest of the season could be agony for fans in Chicago, but it looks like a lot of fun for the teams trying to pull off a major surprise. Here's a quick look at the division:
Since June 25: 21-18
Key player: Anthony Rizzo. More than anyone in the division, he has been tested under pressure in the past and passed. Lots of people around the team think he could have won the NL MVP Award as easily as Kris Bryant last year, and he's quietly having another great season.
They're counting on: The best rotation depth in the division, with Jon Lester and Jake Arrieta on a mission to get the North Siders into the postseason for the third year in a row.
Not so sure about: Their health. Contreras could be out a long time, and shortstop Addison Russell has been on the DL with foot and shoulder injuries. Good thing the Cubs have Alex Avila and Javier Baez.
Remaining games vs. winning teams (and current postseason teams): 19 (3)
Prognosis: They need a .633 winning percentage the rest of the way to win 90, so that's probably not happening. But barring more big injuries, they should be able to use a schedule advantage to hold off the competition.
Since June 25: 19-20
Key player: Jimmy Nelson. Because the front office didn't trade for Sonny Gray or another front-line starter, the burden falls on Nelson to finish off what's been a great season for him. He has never thrown 180 innings in a Major League season, but he should be fine, as manager Craig Counsell has monitored his workload.
They're counting on: Shortstop Orlando Arcia and a cast of talented, enthusiastic youngsters who gained confidence during the 64 days that Milwaukee has spent in first this season will need to lead it to the postseason.
Not so sure about: The depth of the rotation. Zach Davies has done Yeoman's work as the No. 2 starter, and Matt Garza has provided veteran depth in what has been a bounce-back year for him. But the Brewers are going to need a strong return from Tyler Anderson and good work from Brent Suter or Josh Hader to finish off what has been a great season.
Remaining games vs. winning teams (and current postseason teams): 22 (17).
Prognosis: The schedule is a major obstacle, as they have series remaining against the Dodgers and Nationals.
Since June 25: 25-16
Key player: Paul DeJong. Who saw this coming? DeJong was mostly a third baseman in the Minors, but the Cardinals have taken off since DeJong replaced Aledmys Diaz as the shortstop. He could be for the Cards this September what Corey Seager was for the Dodgers down the stretch in 2015.
They're counting on: Carlos Martinez to rise to the occasion and finish strong. It has been an up-and-down year for the Cardinals' best starting pitcher, who is 8-9 with a 3.52 ERA after beating the Royals on Monday.
Not sure about: Whether president of baseball operations John Mozeliak may still make a move to add a bat to a lineup that has produced fewer runs than every NL contender except Pittsburgh. A left-handed power bat makes sense for a rental, especially if the Cards could get one for Stephen Piscotty or Randal Grichuk, whose futures with the organization have become cloudy.
Remaining games vs. winning teams (and current postseason teams): 17 (9).
Prognosis: Classic Cardinals sneak attack. They've positioned themselves to steal the division; all they need is for current trends to continue, although it wouldn't hurt if Dexter Fowler delivered a big finish.
Since June 25: 21-18
Key player: Gerrit Cole. Remember when there was talk about him being dealt to a contender? Turns out no deal was necessary. While Cole's numbers seem so-so, the big stat is the Pirates' 14-9 record in his starts. He'd love for that number to wind up at 21-11 (or 23-9, for that matter).
They're counting on: The veteran presence of players like McCutchen, Jordy Mercer and Starling Marte, who haven't forgotten the three-year postseason run from 2013-15. They've been craving a chance to get back into the spotlight, and they've got it.
Not sure about: What they can expect from Marte. He hasn't been the same dynamic player he was before serving a suspension for PEDs. Marte is hitting .243 and so far has been worth 0.0 WAR. He has averaged 5.2 WAR the past four years, so it's fair to look at him as a key for the stretch run.
Remaining games vs. winning teams (and current postseason teams): 33 (19).
Prognosis: A meat-grinder of a schedule that features four games against the Dodgers in late August finishes with four games against the host Nationals. If the Bucs win the division, they will have earned it.