After the 2008 and 2009 seasons, Kevin Goldstein of Baseball Prospectus rated Josh Vitters as the Chicago Cubs’ top prospect. After the 2010 and 2011 campaigns, he bestowed that honor on Brett Jackson. Vitters was the Cubs’ first selection, and the third overall, in the 2007 draft, and Jackson was their back-end first-round pick in 2009. Together, they once represented the organization’s bright hope for the long run, and they are, in some ways, the last remnants of the team’s pre-Theo Epstein drafts.

By the end of March, it’s unlikely that both will still be on the Cubs’ 40-man roster, and it’s possible that neither will be in the organization at all.

After being called up together in August 2012, both players scuffled badly. Vitters was, essentially, the worst player ever to amass as much playing time as he did, batting .121/.193/.202 in 109 plate appearances and struggling when he appeared in the field. Jackson was quite a bit better. In fact, he was above replacement level, although history already remembers his stint badly. (It’s funny how a sub-.200 batting average and 59 strikeouts in 142 trips can wash out solid defensive work and the expected package of pop and patience at bat.)

Both players needed strong starts to 2013 in order to recover from their nightmarish debuts, but neither got it. That eye-popping strikeout total had the organization panicking over Jackson, who was asked to rebuild his swing and ran into shoulder problems before he could really get the hang of it. Vitters simply had a parade of muscle strains, beginning with his quadriceps in spring camp, then moving to his lower back, hamstring and ribcage. Neither player so much as sniffed the Majors. Jackson had just over 350 plate appearances, some of them taken back in Double-A Tennessee after a mid-season demotion. Vitters batted just 100 times for Triple-A Iowa, all year.

One year ago, their prospect statures had taken severe hits, but Jackson was still considered the sixth-best prospect in the Cubs’ system by Baseball Prospectus. Now, it seems that each is in very real danger of not only never establishing themselves, but never again reaching the Major Leagues. Indeed, it would take a minor miracle to keep at least one from being designated for assignment this spring.

For one thing, the Cubs’ outfield situation is complicated. They have four players locked into outfield slots, in Junior Lake, Justin Ruggiano, Nate Schierholtz and Ryan Sweeney. The fifth player could come from the pool of Jackson, Vitters and Matt Szczur (Jorge Soler is the other outfielder on the 40-man roster, but there’s no way the Cubs will rush their star Cuban prospect to the big leagues so soon), but they all face firm competition from the team’s non-roster invitees, Ryan Kalish, Darnell McDonald, Chris Coghlan, Mitch Maier, Casper Wells and Aaron Cunningham (in about that order of viability).

If any of those non-roster players fights their way onto the 25-man Opening Day roster, they will have to be put on the 40-man roster, too—and the 40-man is full already. Since Szczur has yet to fail at the big-league level (sometimes it helps not to have gotten there), it stands to reason that the first guy cut will be either Jackson or Vitters.

(A brief aside: You may be wondering, if you’re not a geek about baseball’s more intricate roster rules, why being bumped from the 40-man roster is such a big deal. I won’t go into too much gory detail on that score here, but here’s the gist:

MLB allows each team to carry 40 players on its major-league roster at any one time. That includes the 25 who can be on the active roster, plus slots for player on the 15-day disabled list, bereavement list, etc., and some players who are on optional assignment in the minor leagues. I won’t bore you with when players must be added to the 40-man roster, or service-time questions or anything else. What you really need to know is that, once a guy is on the 40-man roster, there are only two ways off of it: serious injury and designation for assignment.

Players on the 60-day disabled list get removed from the 40-man roster, and can be brought back without being exposed to possible claim by other teams once they’re healthy. If you get designated for assignment, though, the team has 10 days to resolve your situation. At some point during that 10 days, you’re placed on waivers, and teams get a chance to claim you for nothing more than a small waiver fee. In the meantime, your team may try to trade you.

If no one claims you and no one wants to trade for you, your team will outright you to the minor leagues. Depending upon your Major and minor-league service time, you may get a chance to elect free agency, or you may not. In any case, if you fall that far, it’s awfully hard to get back up to anywhere anyone in professional baseball really wants to be. Vitters and Jackson, if designated, would probably attract attention, but most teams (not just the Cubs) have a roster crunch at this time of year. It’s possible they’d go unclaimed. It’s still most likely that they would end up in some other organization.)

Nor is a direct replacement the only scenario whereby one of the two could lose their spot. The infield picture is every bit as crowded as the outfield one; it may even be worse. Darwin Barney, Starlin Castro, Donnie Murphy, Mike Olt, Anthony Rizzo, Luis Valbuena and Logan Watkins will all try to crowd onto the active roster, since neither of the likely candidates to be optioned to Iowa (Watkins and Olt) have clear places to play there, either. Christian Villanueva and Arismendy Alcantara, the likely starters at third and second base in Triple-A, are also already stuffed onto the 40-man list.

It gets sticky for Jackson or Vitters, though, if any of those players are leapfrogged by the organization’s top two prospects, Javier Baez and Kris Bryant. It’s extremely unlikely that either will open the season with the Cubs, but if and when each earns their big-league promotion, they will force someone off the roster. It’s perfectly possible that Watkins and/or Murphy would sooner survive as a super-utility player than Jackson or Vitters, who are more strictly limited to outfield duty.

The pitching staff poses another problem. Already, with the roster full and Jason Hammel’s one-year free-agent deal pending completion, one of the members of the 40-man reserve is a dead man walking. If any of the team’s Spring invitees should break though and grab another spot (as I expect at least one of them to, especially Jonathan Sanchez or James McDonald), another spot will need to be cleared.

Rebuilding gets frustrating right about now. The accumulation of talent begins to work against a team, because while it’s important not to rush development or get ahead of oneself, the team still has to play 162 games. The ratio of actual, currently viable big-leaguers to players with upside but little present value flattens to almost 1:1, and casualties become inevitable. Jackson’s lost season doesn’t preclude him rediscovering something, and his athleticism and left-handedness seem to give him a fairly high floor. Vitters actually hit well in Triple-A in 2013, when not injured, as he did at the same level in 2012. The Cubs likely want to see a little bit more before giving up on either player, but in order for that to happen, one of the two almost has to earn a spot at the fringe of the Opening Day roster.