Before 2017, neither Lauer nor Lucchesi had pitched in a five-man rotation for an extended period of time. They're learning to do so on the fly in the Majors, and the Padres are dealing with the effects.
On Tuesday, Lucchesi was placed on the DL with right hip tightness. He's expected to miss one start.
Both pitchers have seen a slight dip in velocity -- particularly in the latter innings of their starts. Manager Andy Green hinted that rest between starts could have something to do with that.
So why didn't San Diego give the rookie duo more exposure to a five-man rotation before they arrived in the Majors?
"We started to," Green said. "They just moved through the system so quickly. These guys are anomalies in the sense that in one year's time, they were in the Major Leagues. ... We thought they'd have enough exposure through this season, and it would be just fine. Injuries got them here quicker than we expected them to be here."
Their quick arrival presents a series of challenges for Green and the Padres, who must find a way to ease two of their top young arms into the grind of a big league season.
Lucchesi owns a 3.23 ERA through 47 1/3 innings. He threw 139 last year. Lauer, meanwhile, has pitched 34 1/3 innings between Triple-A and the Majors, after reaching 122 2/3 in 2017.
There's no hard-and-fast innings cap on the duo, but they'll be monitored closely as the season progresses. San Diego wasn't taking any chances with Lucchesi this week.
"We're going to be very careful with him as we move forward throughout the course of the season, and not just him but Eric Lauer as well," Green said. "We're going to make sure we don't put them in situations that jeopardize the long-term."
How can the Padres do that? For one, they also have experienced starters like Clayton Richard, Tyson Ross and Jordan Lyles in their rotation. Don't be surprised if San Diego works around certain off-days to move one of those veterans forward in the rotation while pushing Lucchesi and/or Lauer back, so they're starting on six days' rest.
As they have in the past, the Padres will almost certainly use the schedule to their advantage, staggering Lauer and Lucchesi so they have extra time off around the All-Star break. It's possible they might be skipped in the rotation once or twice as the season progresses.
"Those are all considerations -- when to give them more rest, when we think they might need it," Green said. "There are also considerations, to a degree, with when we take them out of games."
Lauer and Lucchesi will absolutely get their chances to pitch deep into ballgames, Green said. But those opportunities will likely come when there's an off-day to work around, whether before or after their start. If there isn't, expect a quicker hook.
After all, Lauer and Lucchesi were on a college-baseball schedule, pitching every seventh day, for the most part, as recently as 2016.
"We took one step down [to five days' rest] last year. Now we're taking another step down this year," Green said. "Those guys are making adjustments to it."