If hard-throwing left-hander Brailyn Marquez is part of the Cubs’ future, the future just got a little closer.
The Cubs will add the 21-year-old Marquez, one of their top prospects, to their 40-man postseason roster, along with 11 other taxi-squad players.
The Cubs finalized their 40-man playoff roster after their 7-0 loss Thursday to the Pirates. In addition to Marquez, the roster also includes left-hander Justin Steele, outfielder Albert Almora Jr. and right-handers Tyler Chatwood and Rowan Wick. Chatwood and Wick are on the injured list right now.
Marquez, however, is the player who jumps off the page because he has one of the most electric arms in baseball. He’s listed as the No. 64 prospect by MLB Pipeline and will be the Cubs’ only top prospect eligible for the playoffs.
Marquez, a 6-4, 185-pounder from the Dominican Republic, was 9-5 with a 3.13 ERA in 22 minor-league starts season but never has pitched above Class A. He has been training at the Cubs’ alternate site in South Bend, Indiana.
‘‘He’s throwing the ball really well in South Bend,’’ general manager Jed Hoyer said about Marquez last week. ‘‘I don’t want to comment beyond that, other than the fact that he’s worked really hard with our guys at the alternate site.
‘‘I think he’s progressed nicely. I think he’s gotten better and better, kind of by the week, being there. Many people forget this is a guy that . . . never pitched above [high Class A] ball, so he’s made nice progress this year and is certainly someone we have a lot of high hopes for going forward.’’
The plan for Marquez, at least for now, is to provide depth for the Cubs’ active roster on the taxi squad. He has been working at South Bend to fine-tune his electric stuff. He would still need to be added to the Cubs 28-man roster to pitch this postseason
Sources say the expectations for Marquez should be tempered. The young lefty has hit triple digits on the radar gun and could present some matchup nightmares for opponents in October, but there are still things for him to develop.
The alternate site has been beneficial for the Cubs this season. Several players began the season at South Bend before being called up and contributing to the big-league club.
Right-handers Adbert Alzolay and Jason Adam were in South Bend but have been a part of the bullpen’s recent resurgence. Adam is 2-1 with a 2.38 ERA in 11 appearances. Alzolay developed a new slider while working at South Bend, and it has been a weapon. He struck out seven in four innings of relief Tuesday.
‘‘We put a lot of work into that pitch,’’ Alzolay said. ‘‘I give credit to our pitching coaches down there and the minor-league coordinator, Craig Breslow.
‘‘Down there we have two guys, Ron Villone and James Ogden. I was working with them trying to find that [slider] grip that is helping me now to separate that pitch from the curveball.’’