DENVER -- Right-hander Jhoulys Chacin is healthy and effective, but the Rockies want to make sure, so they're going to assign him one more injury rehab start for Triple-A Colorado Springs on Thursday night.

Chacin, coming back from a chest nerve injury that has kept him off the Major League mound since May 1, threw 84 pitches in 6 1/3 innings and showed good velocity and movement Saturday for Colorado Springs. After checking him out, the Rockies had him throw a 35-pitch bullpen session on Monday that by all reports went well. Now, Chacin will be asked to throw 85-90 pitches Thursday against Albuquerque.

"I think it's just to make sure that he's definitely in the direction and path that we want him to be in, and I personally feel it's a very wise thing to do, rather than push the envelope so hard that we shove him right back," Rockies manager Jim Tracy said. "One extra start would be very good for him."

The volume and intensity of pitches Monday probably made it impossible for him to start against the Brewers on Wednesday, which would have worked into the Rockies' four-man rotation. The Rockies have given no indication that they're willing to back away from the paired pitching plan -- four starters, with three starter-type relievers. But Tracy said he was not going to commit to anything until seeing how Chacin checks out after Thursday's start.

Chacin was 0-3 with a 7.30 ERA in five starts before going to the disabled list. He is eager to start anew.

"I still want to pitch well and try to get my command," Chacin said. "I did good Saturday in the Minor Leagues, and now I feel good. My arm and body feel good.

"If I keep doing what I've been doing, I can get back and pitch better. I've learned from this year."

The Rockies expected Chacin to key a season-opening rotation that did not have veteran lefty Jorge De La Rosa -- who is still recovering from elbow surgery last year, although he did have a strong bullpen session Monday. However, Chacin unexpectedly lost power on his fastball and his arm never felt healthy. It took numerous examinations, and finally a visit to vascular specialist Dr. Robert Thompson in St. Louis, before the nature of the problem was pinpointed.

Chacin, 24, said he might have created the issue by drifting away from the "Jobe exercises" -- a program developed by noted surgeon Dr. Frank Jobe to concentrate on the smaller muscles that are more meaningful to a pitcher than the large muscle groups, which are the focus of most weight programs. Having never had arm issues before, Chacin felt he could add power by working bigger muscle groups, but he has been told his program helped create the chest injury.

The Jobe exercises are back.

"Now that's all I've been doing," Chacin said. "Now I feel the difference and my arm feels good."

Young takes pinch-hit approach in full-time role

DENVER -- The Rockies' Eric Young Jr. used his success as a pinch-hitter for training in his current role as a starting outfielder.

Young leads the Majors with 13 pinch-hits this season. Now he is starting regularly in the outfield because of Michael Cuddyer's right oblique strain and because Todd Helton's season-ending right hip surgery has forced Tyler Colvin to play regularly at first base. It turns out Young is even more successful as a starter than off the bench.

Young's 19 hits from July 31 through Sunday tie him with the Cardinals' Jon Jay for most among National League players, even though Young has started just nine of the 12 games in that span. Young has three hits in four of those recent starts and also knocked an inside-the-park homer against the Dodgers last Wednesday.

Young best fits as a leadoff man. Before his recent success, in a well-meaning effort to work counts and give his teammates a chance to see pitches, Young sometimes let good pitches go for strikes early in the count. Now he is ready to swing earlier in the count. He's also taking a healthier cut.

"In Spring Training, I was kind of feeling for the ball, tapping for it," said Young, 27, in his first full Major League season. "But as a pinch-hitter, you've got to be ready to fire that bat, especially facing late-inning guys. Getting into that role allowed me to get a feel for my overall swing.

"I'm not necessarily firing at the first pitch, but I'm ready to swing earlier in the count. Once you get known as a person who is going to take a lot of pitches, pitchers will just throw a BP fastball just to get ahead of you. You've got to make them think twice about that first-pitch fastball in the middle. Now they throw off-speed for a ball, then get behind in counts."

Young's development is not just on the offensive end. Originally a second baseman who was erratic when first moved to the outfield, Young has improved his routes from all three positions and ability to hit cutoff men to the point that the Rockies look at him as an outfielder, not an infielder doing it in a pinch.

"Give credit to the player," Rockies manager Jim Tracy said. "He sees the opportunity. He's gravitated toward it. I've talked an awful lot about the improvement I've seen defensively.

"He's having a terrific year. There's no getting around it. He does everything he can to send very strong messages. You can't ignore it."

For Young, who still takes grounders at second base, he's not particular where he plays defensively.

"I look at myself as a leadoff hitter, no matter where I play," he said. "The field is better than the bench."

Pomeranz battling soreness, may miss start

DENVER -- Rockies left-hander Drew Pomeranz is not certain to start Wednesday afternoon against the Brewers because of a soreness in his chest area on the left side, manager Jim Tracy said.

Tracy said he and pitching coaches Bo McLaughlin and Jim Wright will discuss the issue, and monitor how Pomeranz (1-7, 5.04 ERA) feels. With days off working in his favor, Pomeranz has not thrown on three days' rest as often as other Rockies pitchers, but he is still battling periodic soreness.

The Rockies entered the season looking to closely monitor the innings thrown by Pomeranz, who threw 119 1/3 between the Minors and Majors last season and has 111 1/3 this year -- 60 2/3 with the Rockies.

In other health developments:

• Outfielder-first baseman Michael Cuddyer, currently on the disabled list with a right oblique strain, said Monday night he will play at Triple-A Colorado Springs on Tuesday and Wednesday on a rehab assignment. He hopes to rejoin the club Thursday to open a four-game series against the Marlins.

• Shortstop Josh Rutledge limped after hitting a ground ball during Sunday's loss to the Giants and received postgame treatment for soreness in his left quadriceps. Manager Jim Tracy kept him out of the lineup on Monday but doesn't expect the problem to be serious. He also rested third baseman Jordan Pacheco.

• A CT scan has revealed that left-hander Christian Friedrich has a fracture of the L-5 vertebrae. The result confirms that he will miss the rest of this season. Friedrich is doing activities with the club but is wearing a solid back brace.