The Dominican Republic's Jimenez is safe. But Venezuela's Morales, younger and sporting a few postseason lumps, would lose his spot in the rotation if the Rockies decide erstwhile ace Aaron Cook has fully recovered from a strained side muscle and is ready to contribute.
That decision is still a day or two away. Rockies manager Clint Hurdle will delay as long as possible a choice he considers borderline unsavory.
"Basically, it's brutal for me to get to this point in time and have to tell a couple guys that they can't participate in the World Series," Hurdle said Sunday afternoon. "This is the one part of the job that I would classify as brutal."
If it's Cook, the Rockies would be regaining their Opening Day starter.
If it's the 21-year-old Morales, he and Jimenez, 23, would comprise the youngest World Series tandem in 41 years. In 1966, the Orioles swept the Dodgers behind the precocious rotation of Dave McNally (23), Wally Bunker (21) and Jim Palmer (20).
Hurdle will also take into consideration an illness that had Morales popping medicine pills in the clubhouse prior to Coors Field workouts late last week.
It's a tough call for Hurdle even on pragmatic levels, a choice between a young, excitable pitcher who has potentially overpowering stuff but can be a risk on the big stage, or an experienced veteran who could bring a calming effect but hasn't pitched competitively in 10 weeks.
Hurdle has already proven unafraid to tweak a winning combination. The Rockies were already a runaway machine, fresh off their Division Series sweep of the Philadelphia Phillies, when Hurdle decided to return Willy Taveras to the roster and into center field.
After not having played for over a month, due to a strained quadriceps muscle, Taveras jumped aboard the speeding juggernaut and neither he nor the team missed a beat.
The Morales/Cook quandary is a little more weighty -- while falling short of being critical, especially if Hurdle chooses to retain the rotation sequence he used in the National League Championship Series against Arizona. That would slot either Cook or Morales to make only one start, in Game 4.
Jeff Francis and Jimenez have already been announced as starters for the first two games in Boston, with Josh Fogg in line to repeat his NLCS Game 3 duties.
Cook would hardly be an Aaron-come-lately to the Rockies' World Series campaign. The 28-year-old right-hander is in his sixth season with the club. He made 25 starts -- still third-most on the staff -- before being waylaid by the injury following his Aug. 10 outing.
"It's been tough to sit and watch," Cook said. "But at the same time, with the way [Jimenez and Morales] have stepped up, they've made it a little easier to go out there and cheer them on."
Yet the veteran of the Colorado staff, declaring himself healthy beyond a doubt, clearly would love to trade in the pom-poms for a game ball.
"It'd mean a lot," Cook said of being added to the World Series roster. "It's what everybody works for at the beginning of the season and basically what you work for your whole career, to get to the World Series. I've been busting my butt to get back."
Colorado has defied logic in so many ways on its sensational run to a National League pennant, but nothing opposed convention as much as the fact that when the Rockies' rotation went down, they began to rise.
Injury claimed three of their starters in a 2 1/2-week span beginning in late July -- Jason Hirsh with a broken right leg, Rodrigo Lopez with a torn right flexor tendon, then Cook.
That siege didn't spoil playoff hopes virtually before they could even spawn because first Jimenez and later Morales stepped right in from Triple-A Colorado Springs and began retiring big league lineups and dropping jaws.
Jimenez went 4-4 in 15 starts, holding hitters to a .228 average with a repertoire that includes near-triple-digit fastballs. Morales went 3-2, and the Rockies won eight of his 10 starts.
Their composure has impressed new teammates as much as their physical talents. At times, the impression has come close to awe.
"All year, he's been filthy," Fogg said of Jimenez, "but he's even stepped it up in the last couple of weeks. It's fun to watch. I'm a little jealous ... but he's been the best pitcher on our staff by far."
"They stepped up and did more than anyone thought they would do, and it took the pressure off me being the only guy left in the original rotation," Francis said. "I go out and watch Ubaldo and Franklin pitch, and they're dynamite pitchers. They're doing things already that a lot of young players wait years to do."
Their contributions have been unexpected, but the kids haven't surprised themselves.
"Everybody's surprised by what I can do, but it doesn't surprise me," Morales said. "I've worked very hard to get here."
Jimenez is even more blunt: "I was sure of what I had."
Being overnight sensations is one thing. Becoming overnight World Series starters is on a different level, however.
"I dreamed about it, sure," Jimenez said. "But I didn't think it would happen so fast."
It may happen a little slower for Morales, if he has to recede into the bullpen and make way for Cook. He doesn't sound like he would mind waiting around for the next time.
"I plan to stay here for a long time," Morales said.