"He needs to command his fastball, simple as that," Acta said. "We've said it over and over and over, but that's what he needs to do."
Huff hasn't commanded his fastball at nearly the rate Acta and pitching coach Tim Belcher would like, hence the 25-year-old lefty's second demotion of the season to Triple-A Columbus on Wednesday.
Cleveland recalled reliever Jess Todd from Columbus to replace Huff on its active roster. Todd's Major League stint could be brief, as Mitch Talbot is slated to start Saturday night in his return from the 15-day disabled list.
If Huff is to reclaim a spot in the rotation, he'll have to first regain the confidence of Acta and Belcher.
"He's got to work on keeping the ball down in the zone," Acta said. "Stats are not going to tell the whole story, because we already know he can go down to Triple-A and pitch well. He has to go down there and make adjustments. I think he understands that.
"Life is about adapting, adjusting and improvising. If it's not working, and obviously it's not right now, then he needs to change."
Coming off a rookie campaign in which he notched a team-leading 11 wins, Huff is 2-11 with a 6.21 ERA in 15 starts this season. He struggled in two appearances since his Aug. 3 recall, yielding eight earned runs -- including three home runs -- over 9 2/3 innings in losses to the Red Sox and Twins.
The Indians selected Huff out of UCLA with the 36th overall pick of the 2006 First-Year Player Draft.
"This is a guy who we need to be good," Acta said. "He's proven in the past that he has the stuff to have success up here. He's left-handed, has a nice, free delivery and can throw 91 mph for the duration of his outing, which is pretty good, if you can command it."
Of late, that command has eluded Huff.
"A lot of people don't realize that it's a big difference between Triple-A and the big leagues," Acta said. "This is the ultimate challenge up here. There's a reason why this is the top level and the elite guys are competing here every day. There are things down there that don't work up here.
"We need David to be successful, without a doubt. At this level, results count. Down there, you want to see development and all that, but when you're up here, results are what we look at."