DENVER -- Troy Tulowitzki wasn't about to make the same mistake twice.
"Playing it safe," Tulowitzki said.
He didn't play it safe on April 29, 2008. Tulowitzki felt a twinge in his left quadriceps while making an off-balanced throw to first, but tried to shake it off. A few batters later, Tulowitzki tore the muscle and missed 46 games.
Tulowitzki wasn't about to go through something like that again.
This time, Tulowitzki listened to his body. He trudged off the field in the seventh inning soon after manager Jim Tracy and trainer Keith Dugger came out to check on him.
"I learned a lot from last year," Tulowitzki said. "After you completely tear something after you stay in there, it makes you realize these people have a job for a reason and they know what they're doing and you should probably listen to them."
The smooth-fielding shortstop said that while the back is feeling better, it was still tight Tuesday. He's not sure when he'll return to the lineup.
"It's better to miss however many games it is [now] than go out there and re-injure myself," said Tulowitzki, who leads all major league shortstops with 24 homers this season.
The Rockies also scratched third baseman Ian Stewart from the lineup after he arrived at the ballpark with a stiff back. Stewart has been swinging a hot bat, too, hitting four homers in his last five games.
"It is disappointing because I do feel good at the plate," Stewart said. "But I don't want it to be something that lingers and could affect me the rest of the year. If I have to take a day or two, so be it."
Although the Rockies lead the NL wild-card race, Rockies manager Jim Tracy said he wouldn't rush Tulowitzki into the lineup until the back fully loosens up.
"When you talk about the low back and think about all the different things that a baseball player is involved in during the course of a game -- bending over to field balls, diving for balls, sliding, running from home to first, first to third, second to home, he's got to be right," Tracy said. "When [the back] does let go, he's going to get immediate relief. Until it does, he's going to be stiff and sore.
"His mobility, it's not even good enough to think about or talk about him being utilized. We've got to get the spasms to let go. That's what we're working on."
Colorado also brought up four players from Triple-A Colorado Springs and designated right-hander Adam Eaton for assignment. The Rockies recalled outfielder Matt Murton and right-hander Jhoulys Chacin from Colorado Springs, and they selected the contracts of right-hander Matt Belisle and infielder Mike McCoy from the Sky Sox.
To make room on the 40-man roster for Belisle and McCoy, the Rockies designated Eaton for assignment and placed infielder Chris Nelson on the 60-day disabled list.