With the MLB postseason set to begin next Tuesday, teams that have clinched a playoff berth or are on the verge of doing so have some crucial decisions to make regarding their 25-man roster, whittling down from the 40-man rosters afforded in September. Here's a look at how those decisions could shape up between now and next week:
Yankees
Among the most interesting decisions for the Yankees will be whom the club designates as its long reliever. Both Jaime Garcia and Jordan Montgomery have been taking turns in a six-man rotation, but neither projects to be in the postseason rotation. Garcia has postseason experience, whereas Montgomery doesn't -- Garcia has started seven playoff games, posting a 3.94 ERA.
Montgomery, however, has been better of late. The rookie left-hander tossed six scoreless innings with one walk and six strikeouts against the Orioles in a 9-3 Yankees win on Sept. 16. Garcia, meanwhile, was hit hard for five runs over 2 1/3 innings at Toronto on Sunday. The other factor to consider here is Garcia's history against the Twins, New York's likely opponent in the American League Wild Card Game on Oct. 3: the 31-year-old left-hander has tossed 11 2/3 innings of one-run ball in two career starts against Minnesota, allowing one unearned run vs. the Twins for 5 2/3 frames with no walks and nine strikeouts on Sept. 18.
Twins
While the big question looming over the Twins right now is whether slugger Miguel Sano (stress reaction in left shin) will be healthy enough to return for the postseason, it's unlikely he'll play in the AL Wild Card Game should Minnesota (magic number of 2 to secure the second Wild Card spot) clinch. The question with more immediate implications, however, is: which starting pitcher will be on the Wild Card Game roster in case ace Ervin Santana, who is lined up to start, is hit hard early or exits early due to injury?
Right-handers Kyle Gibson and Jose Berrios are slated to start on Friday and Saturday, respectively, and would only be available on short rest or in a limited capacity for Tuesday's Wild Card Game. Long reliever Dillon Gee has been strong in that role and will be on the roster, but beyond him that leaves only Bartolo Colon and rookie Adalberto Mejia as options. Colon has plenty of postseason experience, but has struggled in September to the tune of a 9.17 ERA in four starts. Mejia, 24, has never pitched in the postseason but has a 2.45 ERA on the road in 2017. 
D-backs
The D-backs are assured of playing the National League Wild Card Game at Chase Field, and Zack Greinke is lined up to start that game on Oct. 4. Behind Greinke, left-handers Robbie Ray and Patrick Corbin are locks for a potential NL Division Series rotation, particularly since the Dodgers -- whom Arizona would face in that round should it advance -- have trouble with lefties. But who would fill out the other two playoff rotation spots and who would be left out?
It will be a decision between right-handers Taijuan Walker and Zack Godley, one of whom would head to the bullpen. Both have struggled in their last two outings, though Walker has better numbers against the Dodgers this season, with a 3.24 ERA and 17 strikeouts to five walks over three starts.
Indians
The Tribe's incredible run starting in late August has landed it home-field advantage for the AL Division Series, and Cleveland won't have an idea of its ALDS opponent until its race with Houston for the No. 1 overall seed in the AL playoffs is decided. But there are some tough decisions to be made, nonetheless, including who will play left field.
Michael Brantley and Lonnie Chisenhall are the primary candidates to fill this spot if they're healthy, but that's the big question. Brantley has been recovering from a right ankle injury he suffered in early August, while Chisenhall has been dealing with a right calf injury. Veteran Austin Jackson has been playing well in Brantley's place, slashing .307/.355/.486 with four homers since the beginning of August, but Chisenhall's left-handed bat could be key.
Astros
The Astros have a tough decision on their hands when it comes to who will start Game 1 of the ALDS, though it's a good problem to have: left-hander Dallas Keuchel vs. right-hander Justin Verlander.
Keuchel has given up two or fewer runs while going at least six innings in three of four September starts, and should Houston face the Yankees, Keuchel's success against New York speaks for itself: in seven career starts, he boasts a 1.24 ERA and he beat the Yankees in the 2015 AL Wild Card Game. But Keuchel's postseason experience only includes two other appearances in '15, both in the ALDS against the Royals.
Verlander has made 16 career postseason starts, with a 3.39 ERA. He's also been nearly unhittable since being traded from Detroit to Houston, going 4-0 with a 0.64 ERA and 32 strikeouts to just five walks in four starts.
Red Sox
Last year's AL Cy Young Award winner, Rick Porcello, along with postseason veteran Doug Fister, could very well be battling for a spot in the Red Sox's playoff rotation as they approach their final starts of the regular season.
The longtime friends are in the mix, along with Eduardo Rodriguez, to fill out a rotation headed by one of this year's AL Cy Young frontrunners, Chris Sale, and Thomas Pomeranz. Porcello has had a rough season, surrendering a league-high 229 hits and posting a 4.55 ERA. Fister has made nine career postseason appearances (eight starts), with a 2.60 ERA. A lot will be riding on their outings this week.
Dodgers
With the Dodgers' bullpen struggling lately, the intriguing potential of having the club's No. 1 prospect per MLBPipeline.com, Walker Buehler, playing a key role in the postseason is very much on the table.
To what extent would Buehler be used? His ERA since making his big league debut on Sept. 7 is 8.53. But with Pedro Baez and Thomas Stripling struggling, Buehler could be an important right-handed arm out of the bullpen in the middle innings. And after giving up six runs over his first four outings, Buehler has put together back-to-back scoreless appearances.
Nationals
Are eight games at the Major League level enough to earn a spot on a postseason roster? We'll find out in the case of the Nationals, as the club's No. 1 prospect has shined both offensively and defensively over that small sample size. Outfielder Victor Robles, the No. 2 prospect in baseball according to MLBPipeline.com, has the type of blazing speed that could make him an X-factor on the basepaths as a pinch-runner in October. But he's also shown the jump to the Majors hasn't been too much for him.
Robles is slashing .278/.350/.556 with a double and two of the fastest triples Statcast™ has ever tracked for a Nationals player. Robles cracking the playoff roster could bring exciting possibilities for Washington.
Cubs
Unlike a year ago, the Cubs will face some decisions about their postseason rotation as they get closer to clinching a playoff berth. Jacob Arrieta, Kyle Hendricks and Jose Quintana have been strong of late, but veterans Jonathan Lester and John Lackey have struggled.
Outside a hiccup on Labor Day at Pittsburgh, Arrieta has given up two or fewer runs in every start since the All-Star break. His ERA in the second half is 1.97. Hendricks' ERA in 12 starts since returning from a hand injury is 2.34, and Quintana owns a 1.63 ERA in September.
Lester had two particularly rough outings in which he gave up seven earned runs, on Aug. 17 and Sept. 20, but gave the Cubs reason to be hopeful with his last start. On Monday night, Lester limited the Cardinals to a run on five hits over six innings. Lackey, meanwhile, has given up 36 home runs this season, including three over his last two starts, neither of which did he make it out of the fifth inning.
The Nationals, Chicago's likely opponent in the NLDS, have been pretty consistent when it comes to hitting against right-handers vs. left-handers: as a team, Washington is slashing .263/.331/.449 against righties and .273/.328/.448 against southpaws.