PEORIA, Ariz. -- Rockies right-handed starting-rotation hopeful Tyler Chatwood tested his changeup on Sunday afternoon. One of those experiments went awry and ended up a wind-blown home run by the Mariners' Kyle Seager.

But the best part about it is Chatwood doesn't have to explain away giving up three runs, seven hits and three walks in 3 2/3 innings. The Mariners led, 3-2, when the game was called because of rain in the top of the fifth inning. And because the game was not official, the stats were washed away, as well.

So Chatwood can call the experiment a success and not have to discuss the not-so-sterling numbers. Chatwood had a lively fastball and breaking ball, as he expected. Sunday was about developing his changeup, so he will know it's there when he needs it.

"During the season, if I throw five or six in a game, that's a lot," Chatwood said. "That was one of the things ... 'Dac' [pitching coach Bob Apodaca] and I talked about coming out of my last start. He wanted to see more changeups. And in that last inning, I figured I'd try to work it in."

The changeup to Seager was thigh-high, but in Chatwood's defense, the wind carried the hit over the right-field wall. Manager Jim Tracy had no quarrel with Chatwood, who was acquired from the Angels for catcher Chris Iannetta.

Counting Sunday, Chatwood has nine strikeouts to four walks. His willingness to attack the strike zone has put him in good position in the chase for a rotation spot. Chatwood's aggressiveness could also help him become an effective reliever.

Tracy had no issues with Sunday's performance.

"There were some sequences that were very intriguing," Tracy said. "His changeup and the fastball that followed were just explosive stuff."

Chatwood's start Sunday was on short rest, which could explain why he was smooth for the first two innings but struggled in the third and fourth. He threw 61 pitches, but with full rest before his next scheduled outing -- Friday against the Giants -- could throw 80-plus pitches.

Outman's schedule affected by weather

PEORIA, Ariz. -- At least the bad weather that halted the Rockies' game against the Mariners arrived late enough that starting pitcher Tyler Chatwood could throw 61 pitches. However, it played havoc with the pitching schedule of left-hander Josh Outman, who was scheduled to throw about three innings.

Outman, a candidate for the rotation or the bullpen, warmed up before and after the delay. Manager Jim Tracy said it would not be wise to use Outman on Monday against the Angels, since it's better that he give his arm some rest.

Rotation and bullpen candidate Esmil Rogers and bullpen candidate Edgmer Escalona were also supposed to be used on Sunday. It was not clear when they will be worked back into action.

Door open for Nelson to make Rockies

PEORIA, Ariz. -- Rockies infielder Chris Nelson is taking advantage of his best opportunity to make an Opening Day roster.

Nelson, 26, the Rockies' 2004 top Draft pick out of high school in the Atlanta area, hit .250 in 63 Major League games in 2011 while bouncing between the Majors and Triple-A Colorado Springs. Believing Nelson could have a greater role in 2012, the Rockies sent third-base coach and infield instructor Rich Dauer to Georgia to work with Nelson for three days in January.

Manager Jim Tracy has used Nelson at third base, second base and shortstop this spring. Dauer helped Nelson with his fielding.

Now, with the Rockies wanting to see once and for all what they have in Nelson, and with projected starting third baseman Casey Blake battling neck soreness, Nelson has a chance to entrench himself solidly on the roster. He even has a chance of grabbing a starting spot.

Last season, Nelson hit too many balls into the air, and had problems handling the inside pitch. He has worked on those weaknesses. The result so far is a .267 batting average, with two doubles. He has five strikeouts and no walks, so there is still improvement needed. But his progress is real.

"He's taken some good at-bats this spring," Tracy said. "At Maryvale, he took two terrific at-bats against [the Brewers'] Yovani Gallardo. He's doing it against guys that you're going to see pitching in the big leagues."

Worth noting

• The Rockies' Jordan Pacheco played catcher on Sunday. He scooped up a pitch in the dirt and threw out the Mariners' Chone Figgins on a steal attempt, and nearly picked another runner off first base. Pacheco, a solid hitter who can play several infield positions as well as catcher, also drew walks in both of his plate appearances.

• Rockies outfield hopeful Tyler Colvin, who entered Sunday with a .346 batting average and one home run, singled off the right-center-field wall on Sunday. Colvin, an outfielder by trade, played first base on Sunday.

• Tracy said Blake responded well to a full day of baseball activity on Saturday, and could play on Monday against the Cubs. Blake, 38, underwent neck surgery at the end of last season and has missed the last seven days with a sore neck muscle. Before the neck discomfort, Blake was 0-for-9 with four strikeouts.