Hurdle said he put Jimenez, 24, "on notice" Saturday, a day after he lasted just 2 1/3 innings and gave up six runs in what turned into a 13-inning, 8-7 loss to the Dodgers.
"I talked to him about what we need, what we expect, and basically just make sure we're all on the same page -- that he understands that he's the only one here that can make this thing right," Hurdle said. "We can do all the coaching and helping, but what's going on is going on, on the mound with the ball in his hand.
"The challenge for him is to put his foot down and figure this out. He's going to get the freedom to continue to pitch, but we will not continue to go forward with him pitching along the lines that he's pitching now, and he knows that and understands that completely."
Jimenez is 1-2 with a 6.46 ERA in five starts. After the Rockies gave him a 4-1 lead Friday, Jimenez retired just one of eight hitters in the third inning before being lifted. He also finished with three walks, a hit batter and three wild pitches.
"It was the same -- I have to throw down in the strike zone," Jimenez said, explaining what went wrong.
This is the same Jimenez who was called up late in the 2007 season, went 4-4 with a 4.28 ERA in 15 starts while helping the Rockies into the playoffs and was 0-1 with a 2.25 ERA in three postseason starts.
"I think last year he was more calm," catcher Yorvit Torrealba said. "When he was in trouble, he was able to calm himself down and make a pitch. This year, when there's traffic he tries to overthrow."
Hurdle, who also is dealing with inconsistency from rookie left-hander Franklin Morales (1-1, 6.00 ERA in four starts), could be sending Jimenez to the bullpen or Triple-A Colorado Springs if he doesn't navigate traffic better. Veteran right-hander Kip Wells (1-1, 2.29 ERA), who has pitched well in long relief, could be moved into the rotation.
Thomas Harding is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.