DENVER -- Rockies center fielder and leadoff hitter Dexter Fowler left Thursday's game against the Nationals before the top of the fifth inning. He was hit on the right knuckle on his ring finger by a Ross Detwiler pich in the third.

Precautionary X-rays were negative and Fowler is listed as day-to-day. Fowler doubled in the first inning and is hitting .302 with 10 home runs and 26 RBIs. He became the second Rockies outfielder to leave the game. Carlos Gonzalez suffered a left foot contusion when hit by a Jordan Pacheco foul ball while he was on deck in bottom of the first.

Fowler said at first the hand was numb, but swelling ensued and he simply could not grip the bat.

"I didn't know [if it was broken]. I just know it was hurt," Fowler said. "It [the pitch] came way in, and I tried to pull back. It hit me on my knuckle."

Colorado then lost star shortstop Troy Tulowitzki in the eighth inning. Tulowitzki dove for an Ian Desmond ground ball in the frame, but failed to get the ball out of his glove. He remained in the field, but was replaced in the bottom half when Yorvit Torrealba pinch-hit for Tulowitzki. It was later revealed that Tulowitzki broke a rib on his right side and he is expected to miss four to six weeks.

With one out and nobody on in the third, Fowler squared to bunt for a hit, then tried in vain to pull back when Detwiler's pitch broke inside. The ball hit Fowler's hand, which was holding the middle of the bat.

Nationals catcher Kurt Suzuki threw to first, hoping the play would be ruled a bunt into fair territory. As trainers attended to Fowler, umpires deliberated before ruling that Fowler was hit by the pitch.

The injuries occurred a day after the Rockies went to a four-man outfield by designating Eric Young Jr. for assignment to add a 13th pitcher -- right-hander Chris Volstad. Utility infielder Jonathan Herrera replaced Fowler. Herrera has played outfield in winter ball in Venezuela, but he made his first Major League outfield appearance earlier this season. Thursday afternoon was his second.