Black encouraged by Gray's bullpen session

Broken bone in left foot has sidelined pitcher since April

Black encouraged by Gray's bullpen session

DENVER -- Jon Gray took a significant step toward returning from a stress fracture in his left foot on Sunday, and did so without the protective boot he's been sporting for more than a month.

Gray threw his first bullpen session without the immobilizing boot on Sunday morning before the Rockies faced the Cardinals at Coors Field, tossing 30 to 35 pitches in what manager Bud Black described as a live session.

"He was turning it loose," Black said. "His arm is in good shape."

Gray will begin fielding exercises this week while continuing to throw scheduled bullpen sessions over the next week or two, though the primary objective for the right-hander will be increasing his lower-body strength, Black said. Now without the boot, in which he had been allowed to throw while wearing since late April while keeping him immobilized from arching, Gray can begin more intense weight training.

"Now it's just a matter of getting Jon into baseball shape," Black said. "He's got to get his legs underneath him. He's got to get obviously his foot, his ankle, his calf, his legs into baseball game shape. And that's where the next week, 10 days, two weeks, we're headed with Jon. But as far as throwing, outstanding."

Gray sustained the left foot navicular stress fracture on April 13 in San Francisco attempting to field an infield chopper on a play he said he usually avoids. The club's Opening Day starter and ace, Gray compiled a 4.38 ERA over 12 1/3 innings in three outings, all Rockies wins, before landing on the DL. The Rockies have since gone 25-15 without him heading into Sunday's game, which has tempered urgency to rush him back -- particularly with an impactful rookie contingent that has impressed.

After Saturday's 3-0 loss to the Cardinals, Antonio Senzatela, Kyle Freeland, German Marquez and Jeff Hoffman (since optioned back to Triple-A Albuquerque) are a combined 11-3 this month, which marks the most collective wins by rookie starters for a team since A's rookies went 11-5 in September 2009.

At full strength, the Rockies have the rotational depth to stagger their young staff as the season progresses, if needed. None of their starters -- including Gray and Tyler Anderson, and veteran Tyler Chatwood -- have ever crossed the 200-inning threshold in a season. Neither has Chad Bettis, who announced on May 16 that he's completed his final round of chemotherapy for testicular cancer, and hopes to return this season.

Daniel Kramer is a reporter for MLB.com based in Denver. Follow him on Twitter at @DKramer_. This story was not subject to the approval of Major League Baseball or its clubs.