SCOTTSDALE, Ariz. -- It was a bad day for Rockies pitchers.
In Scottsdale, Christian Friedrich made his first start of spring training and allowed two of San Francisco's five home runs as a Colorado split squad lost 11-6 to the Giants.
Chacin pitched for Venezuela in the World Baseball Classic and has been limited to 4 1/3 innings in three Cactus League starts this spring. He reported the back problems on Thursday and the Rockies decided to start Tyler Chatwood against the Rangers on Friday.
"He felt them come on yesterday so we're just being cautious," manager Walt Weiss said. "It doesn't look like anything serious but there is no reason to run him out there 24 hours later to have him make his start. The plan is to give him a couple of innings (Saturday), but we won't stretch him out."
Chacin, 23-31 with a 3.68 ERA in 82 career games (67 starts), was named the starter for Colorado's April 1 opener in Milwaukee by Weiss on Tuesday. He was 3-5 with a 4.43 ERA in 2012, a season that was shortened by a pectoral muscle injury.
Fredrich, who is coming back from his own back problems that have hampered his spring and likely cost him a shot at the starting rotation, allowed five hits -- home runs to Hunter Pence and Brandon Belt -- in three innings. Miguel Batista also allowed four runs in two innings.
Belt raised his spring average to.439 with two homers, a ground-rule double, and a single while driving in four runs.
"This is the time of year, getting closer to opening day, that you want to stay as locked in as possible. I'm seeing the ball well, feeling good and ready to get started," said Belt, who had seven home runs last season but has six this spring, the most of any player in the Cactus League.
Belt hit .275 last year and at 25, feels he is ready to take the next step in his career.
"I'm not the same player I was, from a mental aspect and everything else," he said. "I know what to expect going out there. I know there will be some bumps in the road, but I also know that I can come out on the other side. I'm going in with a lot more confidence this year."
Belt had three hits against lefties, another area he's work hard to improve on.
"It's something to take personally as a left-handed hitter, that you can't hit left-handed pitchers," he said. "I want to show them that I can."
Belt was a triple shy of the cycle in the seventh when he sent a drive to left-center. It cleared the fence.
"I thought I hit it pretty good. If I had hit one down the line, I was definitely going for the cycle," he said.
Nick Noonan and Mark Minicozzi also homered for the Giants, who had 15 hits. Carlos Gonazlez had a two-run homer for the Rockies in the first inning.
Giants pitcher Madison Bumgarner went five-plus innings and struck out five against the Los Angeles Angels' High A team in Scottsdale. He threw 56 of his 87 pitches for strikes, allowing two runs and four hits . Gregor Blanco had a big game for the Giants with a single, double and triple, scoring twice and knocking in one. . Gonzalez, Ben Pauslen and Jonathan Herrera all had two hits for the Rockies.