Buchholz, coming off the best Spring Training performance of his career, gave up two hits in the seventh inning of Tuesday night's 2-1 victory over the Cardinals. Both hits came with two outs, and then he struck out Cesar Izturis. But Hurdle said Vizcaino's turn will come, possibly Wednesday night.
Hurdle said he does not want to use either Buchholz or Vizcaino in consecutive games this early in the season.
"It's a situation we learned from last year with LaTroy Hawkins," Hurdle said.
Hawkins, now with the Yankees, had a heavy workload in April, struggled and suffered a forearm injury. After Hawkins returned, the Rockies worked to avoid using him in back-to-back games and he became one of their best relievers.
"We don't want to give them too much too soon," Hurdle said.
Vizcaino said he is continuing to work on getting his four-seam fastball lower in the zone, and the project is coming along in bullpen sessions. He threw one Sunday.
However, just being in the regular season could help Vizcaino. The Rockies insisted he work on the fastball in game situations. Vizcaino's slider -- a pitch that came together when he played for the Diamondbacks in 2006 and pitching coach Bryan Price had him use a higher release point -- was in fine form all spring, when he used it.
Now Vizcaino is free to use all his pitches.
"In Spring Training, when you're working on something, you have to throw it, to practice," Vizcaino said. "I understand."
"Now my arm is OK. I'll keep working."
Thomas Harding is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.