PHILADELPHIA -- Carlos Gonzalez's strained left knee kept him out of the lineup for Tuesday's series opener against the Phillies, but he said he is feeling better.

Gonzalez, who sustained the injury in Saturday's loss, could play on Wednesday.

Manager Jim Tracy did not rule out Gonzalez pinch-hitting on Tuesday. He also did not commit to his left fielder returning on Wednesday.

"He's still in the day-to-day mode, and we'll have to wait and see how he reacts with regard to that knee," Tracy said. "Could he play tomorrow? It's possible. ... But we just have to wait and see and take it on a day-to-day basis."

Gonzalez, who tweaked the knee in the eighth inning on Saturday and was scratched on Sunday, leads Colorado with a .335 average, 17 home runs, 51 RBIs and nine stolen bases.

Tracy moves faltering Guthrie to bullpen

PHILADELPHIA -- Right-hander Jeremy Guthrie, who has struggled mightily as of late, has been moved from the rotation to the bullpen, manager Jim Tracy said on Tuesday. Tracy will implement a four-man rotation for an undetermined period of time, with each pitcher throwing 75 pitches per start.

"I personally feel that we had to do something that is nonconventional, if you will, and if this doesn't work out, then we'll work on something else," Tracy said.

Tracy notified his starters and Guthrie of his decision before Tuesday's series opener against the Phillies, and he acknowledged the move to go to a four-man rotation is "a little bit outside the box."

The Rockies' rotation has a Major League-worst 6.28 ERA in 338 innings, the second fewest in baseball, and Tracy is concerned about the abundance of work the bullpen was getting.

Tracy hopes that moving Guthrie, who has a 13.50 ERA in his last three starts, will help him get back on track. Guthrie was the Opening Day starter this season, and his name has recently appeared in trade rumors.

"He understood [the move to bump him to the bullpen] and actually came out and said that he'd be ready to pitch tomorrow," Tracy said. "He's not feeling good about where he's at as far as how he's pitching, not the fact that we've had to move him to the bullpen. He's not performing right now."

Rockies await word on Tulo's progress

PHILADELPHIA -- There was no update before Tuesday's game on shortstop Troy Tulowitzki, who hasn't played since May 30 with a strained left groin muscle. Tulowitzki saw sports hernia specialist Dr. William Meyers in Philadelphia on Monday and Tuesday and was scheduled to undergo more tests on Wednesday, manager Jim Tracy said.

The two-time All-Star was hitting .287 with eight home runs and 27 RBIs in 47 games before the injury.

Worth noting

• Troy Tulowitzki fell to second among National League shortstops in the All-Star Game voting results released on Tuesday. Tulowitzki has 1,647,235 votes, 94,125 behind the Cardinals' Rafael Furcal.

• Carlos Gonzalez, previously 10th in the All-Star voting among NL outfielders, dropped to 11th, with 1,120,406 votes.

• Second baseman Jonathan Herrera, who has been on the disabled list with a strained right hamstring since May 23, is "getting very close" to returning, manager Jim Tracy said.