DENVER -- A popular question among Rockies fans is when will they see the return of left-hander Drew Pomeranz, the fifth overall pick in the 2010 First-Year Player Draft, and the key to the deal that sent former ace Ubaldo Jimenez to the Indians last summer.

Bo McLaughlin, who became co-pitching coach for the Rockies after Bob Apodaca stepped down on Tuesday, has worked with Pomeranz at Colorado Springs since the lefty was sent down in May. McLaughlin said Pomeranz has made progress.

Pomeranz was 0-2 with a 5.40 ERA in five starts before the Rockies sent him down to regain the throwing motion he had before the trade. A long period of inactivity before the trade became official, and an emergency appendectomy last summer, seemed to lead to mechanical changes.

Pomeranz is 4-4 with a 2.91 ERA in nine starts with the Sky Sox.

"He's an exceptional athlete," McLaughlin said. "When you throw six innings of no-hit ball [against Salt Lake City on June 19], tough to change that, and the last game he pitched well, too. He's been around 91-92 [mph] and topping out at 93-95.

"It's the quality of pitches he's throwing. The breaking ball is tighter. He's throwing changeups that have good fade to them. He's mixing and matches his pitches. He's using both sides of the plate with his fastball."

McLaughlin said Pomeranz arrived at Colorado Springs with video of his motion before the trade, and the two have been working to restore it.

"He's 23 years old, OK, that's a fact," McLaughlin said. "He's not going to be able to learn what I have the last 20 years coaching and 10 years playing. I can't give him 30 years experience in the last two months. He's going to learn at his own pace.'

McLaughlin also sees progress from right-hander Tyler Chatwood, who is 0-2, 5.79 in nine starts for the Sky Sox.

Chatwood, who pitched 142 Major League innings for the Angels last year and was acquired by the Rockies in an off-season trade, suffered a strained chest muscle shortly after being sent down from the Majors, but is healthy.

"Chatwood's done well and he'll pitch [Thursday] night," McLaughlin said. "He was getting a little bit wishy-washy and getting too deep into counts after he's been ahead. When he got down, he was getting behind in the count and having to work his way back into the count.

"Now he's jumping ahead and messing with him too much and now he's back to 2-2. Again, it's maturity. He's 21. It's taking a deep breath sometimes and saying, OK. They're very talented. How fast they learn and how much they go forward will determine what they can do."

Rockies still adjusting to four-man rotation

DENVER -- The last two games brought out the best and the worst of the Rockies' new and unusual pitching plan, with four starters on a 75-pitch limit and a "piggy-back" starter behind the guy who throws in the beginning.

On Monday, Jeff Francis threw a solid four innings and Josh Roenicke was equally good in two innings behind him. Then the late bullpen -- a strength that often goes unused because too many games spin out of control in the early going -- closed down a 4-2 victory.

But on Tuesday, starter Christian Friedrich was competitive, but Guillermo Moscoso was awful in giving up eight runs in 1 2/3 innings of a 12-5 loss.

Neither was a definitive referendum on the system, manager Jim Tracy said.

"Because of the position that we're in, it's very easy to embrace the fact that all bets are off -- we're 17 games under .500, not five over or three over," Tracy said. "If, in fact, we were five over or four over or three over or in a lead in the division, I don't think this would be received very well. I completely understand that. That's not the case."

This would not be a discussion had the Rockies' starters not pitched at an all-time porous pace. They have a 6.38 ERA, which would shatter the old Major League starter-worst: 6.19 by the 1999 Rockies.

Rockies pitchers who have started boast some rough ERAs -- Francis is at 10.80 in two starts, Friedrich 11.64 in four starts, Jeremy Guthrie, now a bullpen piggy-back pitcher, is 9.53 in five appearances, and Moscoso is 11.88 in five games, including two starts. Lefty Josh Outman, who will start Thursday's finale of the four-game set, is at a high-but-manageable 4.63 in six games, including two starts.

Exactly how far the Rockies go with this rotation is anyone's guess. The notion that Coors Field has taken a dramatic swing back toward the offense, combined with team's attempt to break in multiple young starters, led the club to think outside of the box.

But does this mean that the Rockies have determined they can't win playing at Coors with a conventional rotation? It worked for them in postseason years of 1995 (when the park swung even further to the offense), 2007 and 2009. A normal rotation spearheaded a club record-low ERA of 4.22 in 2010.

Or, in the end, will this be simply a teaching tool for younger starters? It will give prized prospect Friedrich and, whenever they are promoted, Drew Pomeranz and Tyler Chatwood, more starting opportunities and chances to learn for when they are pitching out of a regular five-man rotation in future years.

The next move could be to extend the pitch counts, if the starter is doing well. Francis needed just 66 pitches to get through five innings, but was removed because he was scheduled to start again in three days. However, the Rockies are in a stretch without a day off before the All-Star break. After the break, it's possible that days the team is idle could offer more flexibility.

"As we go forward with this, is this something from a bounce-back standpoint that the number becomes a little higher than 75?" Tracy said. "[If] they show the capability of pounding the strike zone, as a result of that, do you go a little bit further, bearing in mind that three days later they have to be back out there? Once we do that with someone, how do they bounce back with the additional pitches that they throw?

"These are all things that we have to allow to evolve. I don't have definitive answers to all those things until I see them play out between the lines. The bottom line with all this, with as many young arms that we have, what's in their best interest and also what's in the best interest of giving the club a chance to be very successful. It's a day-to-day type thing."

McLaughin ready for pitching coach duty

DENVER -- Bo McLaughlin joined the Rockies on Tuesday as co-pitching coach and vowed to preach what really matters: being aggressive with quality strikes.

The Rockies promoted McLaughin, 56, from Triple-A Colorado Springs, where he was in his first season as pitching coach, after former pitching coach Bob Apodaca was re-assigned on Tuesday.

McLaughlin has been with the Rockies' system for 10 years, including stints as Double-A Tulsa pitching coach and roving instructor, so it's not as if he brings a different message. McLaughlin will work alongside Jim Wright, who was promoted to co-pitching coach, but will continue his duties as bullpen coach.

McLaughlin said he was on board with the new pitching plan of four starters, plus several pitchers that could serve as backups if the starter ran into early trouble.

"People have been doing stuff like this in the past, except maybe having a five-man rotation with three long guys," McLaughlin said. "There's been talk of that in a lot of different organizations for a long time, when I was back with Baltimore, even Montreal. This is not really that big a difference. When you start throwing in off-days and stuff like that, there's going to be normal rest.

"If they want to get the win, throw five innings, they have to go out there and attack the zone with the best stuff they have, in the best locations that they have and make the thing work. That's what we always try to do. I'm not saying they were, because I haven't been here, but if guys go ahead and pace themselves, they're going to have to change to throw more strikes."

McLaughlin, who pitched in the Majors for the Astros, Braves and Athletics from 1976-82, had a pair of meetings with manager Jim Tracy to discuss the particulars of the job.

"I just got here today," McLaughlin said. "Let's just play the game, have some fun. There are enough bad things going around. Let's keep this thing positive and keep it going."