"We haven't made any decisions yet," he said Tuesday after the Angels lost to the Texas Rangers, 15-8.
For most of the spring, the competition for that final rotation spot has centered on right-hander Nick Tropeano, who will pitch Wednesday against Cleveland, and left-hander Andrew Heaney, who pitched 4 2/3 mostly good innings Tuesday.
A few other names — Drew Rucinski, Jose Alvarez — also have floated in from time to time.
Yet, whoever wins that battle may find himself starting the season at triple-A Salt Lake anyway, with the Angels using their final roster spot for a bench player or extra reliever for the first seven games.
"We haven't gotten to that point yet," Scioscia said. "We're too far away. We could put some projected rosters together. But some of it has to do with the flexibility of players, who can go up and down and who you want to burn options with.
"So there are some things to consider."
There doesn't seem to be much separating Heaney and Tropeano. Both are new to the organization, Tropeano arriving from Houston and Heaney from Miami. Each has had a taste of the major leagues, Tropeano making four September starts for the Astros last year and Heaney starting five times for the Marlins.
They even share adjoining lockers in the Angels clubhouse.
"We're kind of both in the same situation," said Tropeano who, at 24, is 10 months older than Heaney. "Both being traded over, young guys, getting a little taste of the big leagues."
Heaney, who appeared to be the early favorite for a starting job, has pitched four times in Cactus League play, giving up 13 runs in 14 innings, although six came in a 3 1/3-inning effort against the Dodgers.
Tropeano, whose last outing came in a triple-A camp game, will make only his second start against big league hitters Wednesday, and that makes it a big game for him.
"You can't just evaluate everything on what happens in a camp game against triple-A hitters," Scioscia said. "You want to see them in the stadium.
"There's a lot to be said of pitching against a major league lineup at this part of the spring. At this stage, you want to bring all the pieces together."
Of the pieces the Angels will use for their evaluation, however, only some will involve numbers. In Heaney's outing Tuesday, for example, the left-hander got ahead of hitters but had trouble putting them away. That doesn't show up in a box score but it could weigh heavily against him.
"We're not looking at just ERA or hits. We're evaluating on commanding their outing, their stuff, hitting their spots. Just rating their pitches," Scioscia said.
Yet, when those ratings are done, there's still a good chance that the winner and loser will open the season with Salt Lake. One could be called to Texas to start April 14 against the Rangers, the first game in which the Angels need a fifth starter, but that stay could be short if Garrett Richards is ready to pitch again in mid-April, as he hopes.
"That's not up to me," Heaney said when asked whether he's thinking about all those possibilities. "I'm doing my best out there to try to make the decision easier."