"But it's a big-time arm, and we feel like there's little bit more development out in front for Eddie."
Butler has been in the Rockies rotation since the start of the season, going 3-6 with a 4.80 ERA in 11 starts. He had two straight appearances last month where he didn't last longer than three innings, and in his previous outing, Butler surrendered a career-high 11 hits in a loss to the Dodgers.
But Weiss there is a "good road map" for Butler to return to the Major Leagues, and the 24-year-old pitcher was still in good spirits, as usual, when he addressed his demotion before Tuesday's game against the Cardinals.
"I'm going to go down there and work on some consistency with the offspeed -- a couple little changes to make it a little bit better and be able to get guys off my fastball," Butler said. "That's one of the big things right now is that guys are comfortable on my fastball.
"So they're going to have me work on that, and when the consistency gets there, they said I'll be the first man back up. They were talking like they want me back up here and want me to help push for the playoffs."
Parker, meanwhile, played in 18 games for Colorado last season over two different stints, picking up five hits in 26 at-bats.
Parker has played 53 games with Triple-A Albuquerque this year, and is hitting .341 (44-for-129) in his last 34 games. Most of his time was spent in the outfield -- 33 games in left field and one in right -- but the Rockies' 2010 first-round Draft pick also played 16 games at first base for the Isotopes.
"I'm just going to take the same approach that I've been taking down there and hopefully, some good things happen," Parker said Tuesday. "I've been feeling good. I started the season off not so hot, so I felt like I needed to make some adjustments and had to deal with some adversity.
"So I feel good at the plate and have been producing."
Dargan Southard is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.