Lyles, who came in a trade with the Astros and is scheduled to pitch Saturday, has a 3.18 ERA and 12 strikeouts. Additionally, he has spent the spring gaining downhill plane on his fastball and, more recently, sharpening his curveball.
"Jordan has done a nice job, and he's been working on some things," Rockies manager Walt Weiss said. "Coming to a new club is tough. All of a sudden, there are some new things to focus on, the level of expectations and that whole thing. He's handled it well and pitched well."
The easiest move would be to go with Morales, since Lyles has a Minor League option. The move would give the Rockies a spot in the bullpen, which could mean the club could keep two righties -- Chad Bettis, who gave up his first run of the spring on Tuesday, but has been stellar for the rest of his nine innings, and Tommy Kahnle, a Rule 5 draftee from the Yankees who has a 0.93 ERA.
But Morales, with a 2.21 spring ERA, has pitched as a reliever most of his career. If Boone Logan has to spend the early days of the season on the disabled list as he completes his recovery from an elbow cleanup, the Rockies will start the year with just one left-hander -- Rex Brothers. But if the Rockies put Logan on the disabled list, it might not be for long; he'd be eligible to return April 5.
Weiss said it's possible the Rockies will announce their 25-man Opening Day roster on Wednesday, but situations such as Logan's are still being discussed.
Thomas Harding is a reporter for MLB.com. Read his blog, Hardball in the Rockies, and follow him on Twitter @harding_at_mlb. This story was not subject to the approval of Major League Baseball or its clubs.