This is not technically the first round of Opening Day roster decisions David Ross has needed to sort through as manager of the Cubs. True, Ross compiled a season-opening roster last year, but the circumstances were markedly different.

During the abbreviated 2020 campaign, the season started in July and Opening Day rosters were expanded to 30 players. This spring, Ross is contending with a 26-man group with only a handful of days left to make the final calls on who will head to Chicago.

"I usually wait 'til the season to not sleep too much," Ross said on Thursday. "But, the last couple nights, it's one of those, you wake up and roll over and then it starts churning in your head."

Ross has spent recent days brainstorming with president of baseball operations Jed Hoyer, the coaching staff and other evaluators in the front office. With one week until Kyle Hendricks fires the first pitch of the season vs. the Pirates, the Cubs are still staring down decisions in the bullpen and rotation, at second base and on the bench.

"I've commented a couple times in the small meetings," Ross said, "where it's like, 'Wow, I didn't know how much I missed out on last year.' And how much work really goes into that and thoughts and questioning this and questioning that, and trying to look at every scenario. It's been a lot, I'll be honest."

And now, a breakdown of the Cubs' looming decisions:

Bullpen
What we know: There are four arms essentially etched in stone, barring something unforeseen. Craig Kimbrel is locked in as the closer, with Brandon Workman, Andrew Chafin and Dan Winkler in the mix as setup options. Ryan Tepera and Jason Adam look like the next two arms on the bullpen's depth chart.

What's left to solve? Two things. First, the Cubs have to determine if they want to open with an eight- or nine-man relief corps. Next, Ross must decide if he wants a second lefty beyond Chafin. Once those two items are solved, then Chicago can begin to piece together the rest of the cast.

With four off-days in the first 19 days, Ross might feel like the staff can get by with just eight relievers come Opening Day. If that's the case, two leading contenders would seem to be righty Shelby Miller and lefty Rex Brothers, who are both non-roster invitees. Some of the other names still in the mix: Adbert Alzolay, Dillon Maples (out of options), Pedro Strop (non-roster) and Brad Wieck.

Rotation
What we know: Hendricks, Jake Arrieta, Zach Davies and Trevor Williams are in. Right-handers Alec Mills, Alzolay and Miller represent the next three options, with Mills (out of options) the leading candidate for the No. 5 job.

What's left to solve? The Cubs have to make a decision on Alzolay, who is expected to have a fourth Minor League option for 2021. That means Chicago could send him to the alternate training site to begin the season without exposing the righty to waivers. And that decision would, in turn, give the Cubs a built-in way to manage Alzolay's innings on the front end of the season.

The puzzle will then be pieced together as the season progresses. Mills looks like the top candidate for the fifth spot to start the year, but he could easily be shifted into the bullpen at times. Alzolay might also be viewed as a versatile multi-inning arm, if the Cubs deem him ready right away. Miller has impressed this spring, and Ross has been intrigued by the possibility of using him in a variety of roles as well.

Second base
What we know: David Bote will be on the Cubs' roster in some capacity. He offers a powerful bat and defensive versatility for second and third base. If Bote is not manning second every day, he could come off the bench, or get starts against tough lefties at third. Ross has not ruled out bumping Kris Bryant to the outfield for such occasions to get that extra righty bat in the infield.

What's left to solve? Is there room for both Bote and Nico Hoerner on the roster? The answer is yes, but the decision could get harder if Chicago opts for a four-man bench. That said, both Hoerner and Bote have been on an offensive tear this spring, and Hoerner offers Gold Glove-caliber defense. After the spring Hoerner has had, can the Cubs really justify sending him to the alternate site?

Bench
What we know: All signs point to P.J. Higgins (non-roster) earning the backup catching role, as veteran Austin Romine continues to work his way back slowly from a right knee setback. The fleet-footed Jake Marisnick has returned from a minor right calf problem with no troubles and is in as the fourth outfielder.

What's left to solve? The second-base situation will have a trickle-down effect here, as will the choice between carrying four or five bench players. With five, the Cubs could easily carry Bote and Hoerner and find ways to work them both into the mix. And that five-man alignment would then allow Chicago to pick two from outfielder Cameron Maybin (non-roster), utility man Eric Sogard (non-roster) and utility man Ildemaro Vargas (out of options).

If Chicago elects instead to carry an extra pitcher, well, that's where the bench decision becomes trickier. The Cubs love what Maybin offers on and off the field, but do they need a fifth outfielder (especially when Bryant and Hoerner can play out there, too)? Are the Cubs willing to risk losing Vargas to another team? These are some of the questions keeping Ross up at night.