MESA, Ariz. -- Cubs pitching coach Tommy Hottovy almost always has a clipboard in hand. There are details about each day's workout, plans for upcoming games and other notes to consider as he maps out his pitchers' schedules.

This spring, things are complicated.

"It's like those jigsaw puzzles every Christmas you break out," Hottovy said on Sunday morning. "There are pieces missing, and you're trying to find them on the floor."

Consider veterans Kyle Hendricks and Marcus Stroman the border pieces. It's a solid place to start when piecing together the rest of Chicago's rotation puzzle. Wade Miley faced hitters for the first time on Sunday, making him one of the key pieces found under the table.

"It's going to come together," Hottovy said.

Here is the latest on how the Cubs' rotation is being assembled.

Hendricks, Stroman look 'ready to roll'
Hendricks piled up around 60 pitches in his three innings of work in Sunday's 13-12 Cactus League win over the Royals. He allowed two solo homers and issued a "bad walk," as he phrased it, but the righty also generated some ugly swings, struck out five and came away content.

"A lot of those are good signs for me," Hendricks said. "It shows that my stuff's working the way it should be. I was able to sequence some pitches well to get those kind of swings that I'm used to seeing in the past. So to be at that point right now in the spring, it felt good."

Stroman is scheduled to start against the Reds on Monday night and will likely build to three or four innings. After that, both he and Hendricks have one start left apiece before they are likely slotted into the season's first two games (April 7-8) against the Brewers.

The way the schedule shakes out, Hendricks is poised to take the ball on Opening Day, but the Cubs have not announced that decision. Either way, Hottovy said it helps the situation this spring that both Hendricks and Stroman are building up steadily for a more normal workload.

"Those two guys," Hottovy said, "especially the way they work and go about their business, they're as good as it comes in terms of professionalism and being ready to roll."

Miley faces hitters in live BP
Following a 17-pitch live batting practice on Sunday morning, Miley headed behind the backstop to get some pitch data feedback. The veteran lefty was pleasantly surprised by what he heard from the Cubs' staff.

"Better than I expected. I'm moving along," Miley said. "A couple of days off, and I'll get back after it again."

In experience and ability, Miley would be considered the Cubs' No. 3 starter. During this abbreviated spring and the "veteran" program he has been following, it is possible Chicago delays his first start of the season.

Hottovy said the likely next step for Miley would be a two-inning live batting practice. If that goes well, an outing in a Cactus League game could follow. And, if necessary, the Cubs could leave Miley in Arizona to continue to build up his volume while the team is in Chicago for the opening series.

"Absolutely," Hottovy said. "We have to look at this as kind of like in sections. Our first section is that first four-game series. Then we technically don't need a fifth starter until Game 9 [April 16 at Colorado] of the season. So it's taking all those things into consideration."

The rest of the puzzle
The Cubs could also view their rotation in sections right now. Hendricks and Stroman are at the top. When Miley will slot in remains to be seen. Then there is the group of arms who fall into a category of mix and match accordingly.

"It's so unique, right?" Cubs manager David Ross said. "There are a lot of guys that are still ramping up and we can't make any hard, fast decisions right now."

Lefty Drew Smyly threw two impressive innings in his Cubs debut on Saturday. Justin Steele and Alec Mills have built up to multiple innings as well. Righty Keegan Thompson threw a two-inning live batting practice on Sunday, and lefty Daniel Norris followed Hendricks with two innings of scoreless relief against Kansas City.

Ross, Hottovy and the Cubs' staff will consider pairing pitchers up for "piggyback" outings at the start of the season. Right now, though, not even Hottovy's clipboard has those details sorted out.

"To say each piece is going to fit perfectly in the puzzle is still to be determined," Hottovy said. "I think we just have to make the best decision we can for each guy."